Your opinion needed on Allendale overclocking

[Clones123]

AnandTech reports here that they pushed low-end 1.8v DDR2-533MHz memory to 800MHz with 4-3-3-8 timings at 2.1v indicating that high-end, low-latency memory is NOT a necessity for overclocking (even if high-end RAM does provide the very best results).
http://www.anandtech.com/mb/showdoc.aspx?i=2797&p=17


Meanwhile, Xbitlabs reports here that (quote); ?even with bad timings DDR2-800 works faster than DDR2-600 with the best timings.?
http://www.xbitlabs.com/articles/memory/display/core2duo-memory-guide_8.html

Which report is correct in your opinion?

Regardless, it would seem from what I?ve read that having memory that will initially post at stock 1.8v is important. For instance, many people report first-day boot failures with 2.1v OCZ modules ? having to resort to low-end 1.8v RAM so they can get into BIOS and increase their vdimm setting before the high-end RAM will work. Well, I supposed I can borrow a stick of cheap DDR2 memory from somewhere for a day if I have to.


Moreover?.as you know, the Allendale/Conroe CPU multipliers look like this:
E6300 = FSB x 7
E6400 = FSB x 8
E6600 = FSB x 9
E6700 = FSB x 10

The Asus P5B Deluxe (which I?m most interested in) has the ability to override the locked CPU multiplier down but not up. (Asus reportedly says that some chips at random can be unlocked both down AND up but I haven?t seen anyone confirm that). Anyway, numerous articles I?ve read claim that the Allendale/Conroe chips with higher CPU multipliers overclock better since the FSB doesn?t have to be pushed as far before the CPU maxes out (lower FSB puts less stress on the NorthBridge).

However, this VERY interesting thread suggests the opposite ? that CPU?s with LOWER multipliers overdrive the NB less.
http://www.bleedinedge.com/forum/showthread.php?t=23803

I?d hate like hell to spend extra $$ for an E6400, then have to unlock it DOWN to a 7x multiplier and then also find WORSE overclocking results than if I?d bought an E6300 in the first place!

BOTTOM LINE:
In your opinion....
- is DDR2-533, DDR2-667, or DDR2-800 memory the best overclocking value??
- is the best overclocking choice an E6300 or an E6400 ??
- which Allendale Stepping and Revision seems most ideal ??


Your opinions and experience, please.



Here's the system I'm planning...

ASUS P5B Deluxe
Core 2 Duo E6400 @ 3.2GHz (400fsb x 8)
CORSAIR XMS2 2GB DDR2-800 TWIN2X2048-6400
Zalman CPNS9500 AT
ENERMAX Liberty 400W Power Supply
Antec Solo ATX mid-tower (with 2x optional 92mm case fans)
Seagate Barracuda 7200.10 320GB SATA (3.0Gb/s 16MB Cache)
BFG Tech Geforce 7900GS 256MB
PowerColor Theater 550 PRO PCI-e TV Tuner
Memorex DVD+/-RW Dual-X1 EIDE (reused)
WinXP-SP2 Pro

OTOH, if I could pull it off, I'd be a lot happier with a 3.2GHz overclock of a E6300 (457fsb x 7) and low-end A-DATA Vitesta 2GB DDR2-533 pushed to 800MHz 4-3-3-8 @ 2.1v. After all, the whole point of overclocking is seeing how much you can do with how little.

It's worth mentioning too that I'm seeking a 100% stable 24/7 overclock on air that doesn't take three months to dial-in. With kids keeping me busy, time becomes part of the "how little" equation too!

 

[customcoms]

It is basically a toss up from what I've been reading: The extra cache in the E6600 and up generates more heat, resulting a in a lower overclock mhz wise, but its comparable to a 200mhz higher clocked E6300/E6400. The Allendales tend to be achieveing higher clock speeds than their pure conroe brothers, but in the end its all about the same performance wise. And its always luck of the draw with a cpu as to how fast it can go. In which case, having a faster base cpu helps because if it can't be overclocked very much, its still very fast (although all the C2D's are really fast) For the P5B Deluxe, people say go with a higher multi because the FSB can't be pushed as high as the P965 chipset boards.

Also, the best ram value wise based on that article appears to be the A-Data sticks, which I can only find at newegg and they're always out of stock. They were $153 2 months ago (out of stock of course). Now their out of stock and up to $214. Their DDR2-667 sticks are the same price for a 2GB kit and instock: http://www.newegg.com/Product/Product.asp?Item=N82E16820211061, but you should probably be looking at some G. Skill: http://www.newegg.com/Product/Product.asp?Item=N82E16820231061 at that price point. Now is not the time to be buying ram, it is EXTREMELY expensive!!!

 

[harpoon84]

customcoms, the P5B Deluxe *is* a 965 board, and one of the best for O/Cing too.

I personally think the E6400 strikes the 'sweet spot'. The 8x multi means a 400FSB x 8 = 3.2GHz - a reasonable, if not spectacular overclock.

Why is this important? Well, firstly, 400FSB means DDR2-800 speeds using the 1:1 RAM:FSB ratio. As the OP pointed out, even budget DDR2-553/667 sticks can usually hit DDR2-800 speeds with added voltage.

This means even budget RAM can be used on the E6400 to achieve decent overclocking results.

400FSB on an E6300 means 'only' 2.8GHz, while 400FSB on an E6600 equals 3.6GHz- but you'll need a good clocking chip + good cooling to achieve that.

A 400FSB E6400 @ 3.2GHz should only require a modest boost in voltage to achieve such speeds, if in fact it is needed at all, so heat should not be a big issue too.

 

[MADMAX23]

Originally posted by: harpoon84
customcoms, the P5B Deluxe *is* a 965 board, and one of the best for O/Cing too.

I personally think the E6400 strikes the 'sweet spot'. The 8x multi means a 400FSB x 8 = 3.2GHz - a reasonable, if not spectacular overclock.

Why is this important? Well, firstly, 400FSB means DDR2-800 speeds using the 1:1 RAM:FSB ratio. As the OP pointed out, even budget DDR2-553/667 sticks can usually hit DDR2-800 speeds with added voltage.

This means even budget RAM can be used on the E6400 to achieve decent overclocking results.

400FSB on an E6300 means 'only' 2.8GHz, while 400FSB on an E6600 equals 3.6GHz- but you'll need a good clocking chip + good cooling to achieve that.

A 400FSB E6400 @ 3.2GHz should only require a modest boost in voltage to achieve such speeds, if in fact it is needed at all, so heat should not be a big issue too.

Just like he says...Clones123...., harpoon84 is completely right!
Take a look at my sig, I am using P5B Deluxe + a E6400 + cheap DDR2 800 GEIL Ram.

 

[Madellga]

E6400 at FSB 400 is a good choice. No high VCore required, no über expensive ram.

Regarding the E6600 remarks, I tried 2:
1) First would not go above 3.0GHz
2) Second reachs 3.4GHz, low VCore as the 6400 (1.375V).

To be honest, it's necessary to choose the right components, but there is a bit of luck in it.
Just don't expect higher O/C than this without pushing the system much harder for a 24/7 stable operation.

 

[Clones123]

I've been looking at this some more and the Xbitlabs article, though fairly comprehensive, has a big flaw; they didn't show the effects of overclocking any of the RAM. Thus, their conclusion should have read, "even with bad timings (memory run at) DDR2-800 works faster than (memory run at) DDR2-600 with the best timings.?

Duh. With Core 2 Duo, RAM performance is more clock-dependant than it is latency-dependant. Essentially, they were saying that a 300MHz FSB with tight RAM timing doesn't perform as well as a 400MHz FSB with loose RAM timing. That doesn't contradict the AnandTech article at all - the point just wasn't clearly made by Xbitlabs. AnandTech took value RAM and overclocked all of it to DDR2-800 with the best timings/voltages and found it surprisingly close in performance against high-end RAM with tighter timings.

Unfortunately, it looks as though word is out on the A-DATA Vitesta 2GB DDR2-533 (ELJKD1A16K) kit ? now that it?s back in stock at Newegg, the price has jumped up to $215 (when it was out-of-stock a few days ago, the price was only $150). Oddly, that?s the same price as the faster A-DATA Vitesta 2GB DDR2-667 kit after rebate (ADQPE1A16K)

Regarding the NBCC/strapping issue - okay, it looks as though a E6400 run with a 7x multiplier won't perform as well as a E6300 at it's own native 7x multiplier. OTOH, I'm not seeing many people benchmarking the E6400 with a reduced multiplier anyway (though some have).

Based on the responses I've gotten on four different overclocking forums, I'm thinking that, for me, the E6400 with Corsair XMS2 PC6400 memory (5-5-5-12 @ 1.9V) is the safest bet for a solid overclock on air.

I found the information below interesting though. What's with the variety of DIMM's all using the same IC's ("ProMOS 667MHZ, CL5, 0.09u 64Mx8 ETT") ?
---------------------------
Corsair IC Inquiry Thread
http://www.houseofhelp.com/forums/showthread.php?t=44365

Value Select Modules
Value Select modules are built with RAMs that are procured at the wafer level and are packaged and tested to our specifications. As such, they are not available as individual ICs, only as modules. This approach allows us to ship product with very good performance characteristics, low product cost, and a very low return rate.

DDR2 - XMS
XMS, or eXtreme Memory Speed, is the process that Corsair uses to take ICs rated at one speed and verify/guarantee their operation at another speed. Since specifications have not been generated to accurately specify operating parameters, Corsair gives these parts an XMS rating. For example, since PC2400 does not exist according to any valid standards institution, Corsair parts are called XMS2400.

5400C4
CM2X1024-5400C4 XMS5402 v2.10 0628134-2 = Micron, 64Mx8, DDR2-533, CL4, Die Rev D
CM2X1024-5400C4 XMS5402 v5.2 0633071-3 = PCS DDR2, 675MHz, CL 4, 64x8 90nm ETT
CM2X1024-5400C4 XMS5402 v5.2 0633071-5 = PCS DDR2, 675MHz, CL 4, 64x8 90nm ETT
CM2X1024-5400C4 XMS5402 v7.1 0629230-11 = ProMOS 0.09u 64Mx8 ETT Rev E

6400
CM2X1024-6400 XMS6405 v1.4 0606096-2 = Micron, 64Mx8, DDR2-667, CL5, Die Rev D
CM2X1024-6400 XMS6405 v4.1 0609102-1 = Infineon AENEON, Die Rev B, 64M X 8 Rev B
CM2X1024-6400 XMS6405 v4.1 0626413-3 = Infineon AENEON, Die Rev B, 64M X 8 Rev B
CM2X1024-6400 XMS6405 v5.1 0634287-2 = ProMOS 667MHZ, CL5, 0.09u 64Mx8 ETT
CM2X1024-6400 XMS6405 v5.1 0631252-2 = ProMOS 667MHZ, CL5, 0.09u 64Mx8 ETT
CM2X1024-6400 XMS6405 v5.1 0631252-9 = ProMOS 667MHZ, CL5, 0.09u 64Mx8 ETT
CM2X1024-6400 XMS6405 v5.1 0633171-6 = ProMOS 667MHZ, CL5, 0.09u 64Mx8 ETT
CM2X1024-6400 XMS6405 v5.1 0629230-7 = ProMOS 667MHZ, CL5, 0.09u 64Mx8 ETT

6400C3
CM2X1024-6400C3 XMS6403v1.1 0619028-4 = Micron, 64Mx8, 2-667 CL5, Die Rev D [/b]

6400C4
CM2X1024-6400C4 XMS6404 v1.1 0626099-3 = Micron, 64Mx8, 2-667 CL5, Die Rev D
CM2X1024-6400C4 XMS6404 v1.2 0620097-1 = Micron, 64Mx8, 2-667 CL5, Die Rev D
CM2X1024-6400C4 XMS6404 v2.1 0635221-22 = ProMOS 667MHZ, CL5, 0.09u 64Mx8 ETT

6400PRO
CM2X1024-6400PRO XMS6405v1.1 0610028-1 = Micron, 64Mx8, DDR2-667, CL5, Die Rev D
CM2X1024-6400PRO XMS6405v3.1 0609115-2 = Infineon AENEON, Die Rev B, 64M X 8 Rev B
CM2X1024-6400PRO XMS6405v1.3 0610028-1 = Micron, 64Mx8, DDR2-667, CL5, Die Rev D

8500C5/C4
CM2X1024-8500C5 XMS8505v1.2 0620114-1 = Micron, 64Mx8, 2-667 CL5, Die Rev D
CM2X1024-8888C4D XMS8804v1.1 0634174-2 = Micron, 64Mx8, 2-667 CL5, Die Rev D



Why pay extra for the 6400C4 when the cheaper standard 6400 uses the same IC's?

http://www.houseofhelp.com/forums/showthread.php?t=52351

XMS2 6400.......is tested at 800Mhz with timings of 5-5-5-15 @ 1.9 V
XMS2 6400C4...is tested at 800Mhz with timings of 4-4-4-12 @ 2.1 V
XMS2 6400C3...is tested at 800Mhz with timings of 3-4-3-9 @ 2.1 V

I have to wonder though - how often might one get 6400C4 timings out of regular 6400 just by increasing the vdimm to 2.1 V ?

 

[Clones123]

I noticed a serious mistake in my configuration: turns out that the originally spec'd Antec NeoHE 500W power supply carries only a measly 17 amps on the 5v rail. Even the higher-rated Antec NeoHE 550W carries only 20A on the 5v rail (and 3x 18A on the 12v rails). Whoa - what's up with THAT!? All the other power supplies I looked at carry around 30-50 amps on their 5v rails.

I changed my spec to include an ENERMAX Liberty 400W power supply which carries a more respectable 28A on the 5v rail.

Original -
Antec NeoHE 500W specification
+12v1 = 17A
+12v2 = 17A
+12v3 = 17A
+5v = 17A (huh?)

Revised -
ENERMAX Liberty 400W specification
+12v1 = 20A
+12v2 = 20A
+5v = 28A (much better)


I know that 400 watts doesn't sound like much but the eXtreme Power Supply Calculator (http://www.extreme.outervision.com/psucalculator.jsp) conservatively estimates a mere 307 watt power requirement for my system even with optional case fans. Adding an additional hard drive (probable) and a second DVD-RW drive (unlikely) still only takes me up to 345 watts.

Some folks might be more comfortable upgrading to the ENERMAX Liberty 500W but the specs really don't look at lot different...

ENERMAX Liberty 500W specification
+12v1 = 22A
+12v2 = 22A
+5v = 30A

Have a look at "Power Supply Fundamentals & Recommendations" which explains a lot:
http://www.silentpcreview.com/article28-page1.html

 

[DrMrLordX]

Why are you so concerned with the +5v rail? From the article you linked at silentpcreview.com:

"HIGH 12V LINE RELIANCE

The high reliance of current systems on the 12V is dramatic compared to even just a couple of years ago, and the evolution of the ATX12V spec reflects this change. Almost any system assembled from current components will draw the vast majority of current from 12V, in some cases, as much as 90% at load. This is one of the factors in increasing efficiency. It is generally easier to obtain higher efficiency in the conversion from 120VAC to 12VDC rather than 5VDC or 3.3VDC.

We recently studied the power distribution in half a dozen systems of varied configuration to confirm the high 12V reliance first hand and reported our finding in the article, Power Distribution within Six PCs. In all the systems the current draw on the 5V and 3.3V lines was a maximum of just 5A! Note that in dual 12V line models, 12V2 is supposed to only supply the AUX12V (2x12V) 4-pin plug, which feeds only the CPU. 12V1 is supposed to supply 12V to all the other components that require it. This can be a potential problem in some high end gaming systems; see the sections on Dual 12V Lines on the next page."

The 12v rails are the most important thing on modern PSUs. You can probably get away without giving the +5v or +3.3v rails any attention at all.

 

[Clones123]

Originally posted by: DrMrLordX
Why are you so concerned with the +5v rail? From the article you linked at silentpcreview.com: " You can probably get away without giving the +5v or +3.3v rails any attention at all.

Initially, I did follow the above advice until my attention was drawn to the 5v rail specs of the Antec PSU by a complaint in Newegg's User Reviews. While the 5v rail may not be a problem, I'm suspicious of why the Antec Neo HE 500 and 550 units are amp-rated so far below competing models - it throws a red flag that I can easily avoid.

I studied the tier-1 PSU manufacturers like PC Power & Cooling and Seasonic S-12 but found the former extremely expensive and the latter having a high failure/DOA rate on Newegg. That left me with tier-2 mfg's like Xclio and Enermax.

 

[lopri]

Enermax is a big no-no. Go with the Seasonic or even OCZ. Recent Seasonic PSUs shouldn't have the compatibility issue with mobos. Neither should Antec's. Just avoid Enermax.

 

[Clones123]

Originally posted by: lopri
Enermax is a big no-no. Go with the Seasonic or even OCZ. Recent Seasonic PSUs shouldn't have the compatibility issue with mobos. Neither should Antec's. Just avoid Enermax.

Can you elaborate with details or a link maybe? User reviews at Newegg on the Enermax units are stellar - better in the aggregate than the Seasonic and better than Antec. Seems a bit of a lark to give a warning yet provide no real information, yes?

"If indeed the sky is falling Mr. Little, might you show us the bit of it that hit you on the head?"

 

[DrMrLordX]

Originally posted by: Clones123

Initially, I did follow the above advice until my attention was drawn to the 5v rail specs of the Antec PSU by a complaint in Newegg's User Reviews. While the 5v rail may not be a problem, I'm suspicious of why the Antec Neo HE 500 and 550 units are amp-rated so far below competing models - it throws a red flag that I can easily avoid.

I studied the tier-1 PSU manufacturers like PC Power & Cooling and Seasonic S-12 but found the former extremely expensive and the latter having a high failure/DOA rate on Newegg. That left me with tier-2 mfg's like Xclio and Enermax.

Word of advice: pay little or no mind to people leaving reviews on NewEgg. They frequently don't know their stuff.

You do not need to worry about 5v and 3.3v rails much. It is often the hallmark of a cheap/weak PSU to claim a high wattage rating and hide it all on the 5 or 3.3v rails. Seasonic does not have high failure rates, either (Antec is a problem there, however). It should be noted that some of Antec's more-reliable high-end units are actually made by Seasonic.

The only thing wrong with most Seasonic units is that they're a bit overpriced.

Enermax is okay and the Liberty series usually gets good reviews. You might also want to look at Fortron. Personally I'd avoid Antec.

 

[lopri]

I should say I don't know much about the Liberty series from Enermax. So if you are thinking of one of the Liberty series, ignore my comment. But before that, I've seen countless quality control problems with Enermax PSUs, most glaring one being this.

http://www.hexus.net/content/item.php?item=1359&page=19

I had the same PSU in the review and went through numerous stability issues. Also I have never known Enermax for using quality components. I think they cut as many corners as possible to reduce cost. I'd be more comfortable with Seasonic. PC P&C will give you peace of mind, but as you know the price is absolutely ridiculous and so is noise. I'd also look into Zalman's offerings for 300~500W range. OCZ Modstream 520W is a fantastic PSU (heroic 12V performance), if you don't mind the thick/short cables.

 

[Clones123]

Originally posted by: lopri
http://www.hexus.net/content/item.php?item=1359&page=19

OCZ Modstream 520W is a fantastic PSU (heroic 12V performance), if you don't mind the thick/short cables.

Good article - thanks much for the link. The Modstream model's thick, stiff cables are indeed something I'd like to avoid which is why I'd already crossed them off my list. OCZ's Powerstream and Gamestream models look pretty good though.

Unfortunately, the BFG GeForce 7900 GS on my build list specifies a 22A +12 V rail which eliminates a LOT of multi-rail PSU's.

 

[myocardia]

Originally posted by: Clones123
Unfortunately, the BFG GeForce 7900 GS on my build list specifies a 22A +12 V rail which eliminates a LOT of multi-rail PSU's.

Well, you're stuck between a rock and a hard place, then, aren't you? There's only one psu company that's making psu's guaranteed to supply 22A on either of it's 12v rails, Enermax. Well, on both of it's higher wattage Liberty's, at least.

 

[Vaterland]

Boy, oh boy.

"Unfortunately, the BFG GeForce 7900 GS on my build list specifies a 22A +12 V rail which eliminates a LOT of multi-rail PSU's."

Want to hear something? I have Asus 7900 GS powered by Antec's NSK 6500 stock PSU rated at 430W, 372W available on 12V rails. It runs perfectly fine along E6400@3.2 and a bunch of stuff like a hard drive, DVD-RW, 2*512RAM,3 case fans. The 7900GT's peak power consumption is 50W! article at Xbitlabs That's like nothing.

"I changed my spec to include an ENERMAX Liberty 400W power supply which carries a more respectable 28A on the 5v rail." - and why exactly do you need 28A on the 5V rail? Check out the power distribution SilentPC review I claim that Antec and Seasonic adopted the most intelligent power distribution on their PSU's up to date. Show me any other PSU 430W outputing 384W on their 12V rails. Hell, the NeoHE 550W can do 504W! That is just ... plenty.

"BOTTOM LINE:
In your opinion....
- is DDR2-533, DDR2-667, or DDR2-800 memory the best overclocking value??
- is the best overclocking choice an E6300 or an E6400 ??
- which Allendale Stepping and Revision seems most ideal ??"
my rig is P5B delux, E6400@3.2, Kingston PC5300 667MHz, CL5 working just fine at 800MHz. My guess is that this is the best bang for buck. P5B has a very peculiar way of working with the FSB and therefore it's much easier to get 401MHz FSB working than 360-380 MHz. E6400 offers a slightly higher multiplier (high resulting frequency), compared to E6300, without compromising its overclocking ability.

 

[lopri]

I'm assuming multi-rail PSU = dual (or more) 12V lines? If so, the only PSUs with 'true' multi 12V lines are PC P&C's 850W / 1KW series. All other PSUs specifying dual 12V is 'pseudo', in that they all have one power limiter internally and just split them into two. This has no performance/stability benefit whatsoever. (other than minor safety concern you will never run into, unless you like to play with PSUs case-open while taking shower) So going with a single-rail 12V is a smart move on your part.

http://forums.silentpcreview.com/viewtopic.php?t=23916

Don't trust everything in that forum (it's a different crowd there) but this article clears a lot of the myth regarding dual 12V lines.

 

[myocardia]

lopri, in case you hadn't noticed, there have been a few changes in the past 16 months in the way power supplies are designed. What's in that 16 month old thread isn't exactly accurate, in today's computing world.

 

[Vaterland]

"Well, you're stuck between a rock and a hard place, then, aren't you? There's only one psu company that's making psu's guaranteed to supply 22A on either of it's 12v rails, Enermax. Well, on both of it's higher wattage Liberty's, at least. "

Are you trying to convince us all here, that all those folks with ATI X19xx, Nvidia 79xx are running their video cards on a 1kW PSUs from Enermax? This is just insane. Things I learn on this forum are just getting crazier every day. A 380W PSU would run the 7900GS just fine! Some people are trying to make things more complicated then they are. Life is simple. Everything else are just myths.

 

[myocardia]

Originally posted by: Vaterland
"Well, you're stuck between a rock and a hard place, then, aren't you? There's only one psu company that's making psu's guaranteed to supply 22A on either of it's 12v rails, Enermax. Well, on both of it's higher wattage Liberty's, at least. "

Are you trying to convince us all here, that all those folks with ATI X19xx, Nvidia 79xx are running their video cards on a 1kW PSUs from Enermax? This is just insane. Things I learn on this forum are just getting crazier every day. A 380W PSU would run the 7900GS just fine!

Vaterland, your knowledge of psu's seems to leave much to be desired. Enermax has never made a 1,000 watt Liberty model. And there are many 380 watt psu's that would choke trying to run a 7900GS, along with a 3.2 Ghz C2D. A good 380 watt psu would do it, no doubt, but not any, as you seem to be implying.

 

[Vaterland]

1kW Enermax was just a figure speech. And yes, I agree, I am talking about a good 380W PSU, like NeoHE 380, which can output 336W on its 12V rails or Enermax 400W with 360W output on 12V. Find me another 380W PSU that can do that. Tagan? 264W, Topower? 300W. I spent a whole month researching for every single component of my new comp I build 2 weeks ago. Believe me, the PSU only took me a week. The thing is that some of current PSUs are designed with the 5 years ago technology in mind. I don't understand that. Who for god's sake needs 200W on 5V? All I'm saying is that there are PSUs SLI ready with total output 500W. Well, if 7900GS needs 22A (LOL) take it times two and ... well, let's get a nuclear power plant ourselves. Unless this 500W PSU can do 44A Look, I am not an expert. I don't claim I am. However, just a little research is enough to find out that all this PSU power hoopla is just plain funny.

 

[NoStateofMind]

Well you wanna run an OC'd processor and a X1900/7900GT/GTX on a 400W PSU? Be my guest! Do not come here complaining about your PSU frying your system! I simply don't want to hear it. You have all the knowledge you need in your own head (evidentally). Speaking from experience, my 400W PSU took my motherboard with it. That system had a P4 3.0, X800XT. Within 6 months it crapped.

Just remember, when your system craps out, it's not because of the 400W PSU :disgust:

 

[Clones123]

Question and prompt answer from BFG Tech:

-----Original Message-----
To: 'support@bfgtech.com'
Sent: Tuesday, October 10, 2006 12:26 PM
Subject: Power Supply requirements for BFG Tech Geforce 7900GS ??

I'm interested in purchasing a BFG Tech BFGR79256GSOCE Geforce 7900GS. However, I noted on your web site that this card requires a PSU with a minimum 22A rating on a +12 V rail (and 28A for an SLi configuration). http://www.bfgtech.com/7900GS_256_PCIX.html

Unfortunately, that's a steep requirement not met by many power supplies. For instance, even the high-end SeaSonic S12-600 ATX12V 600W power supply (Nvidia SLi Certified) only carries 18A on each of two +12V rails. I further noted that Nvidia's own web site under "SLi power supply recommendations" (http://nvidia.custhelp.com/cgi-bin/nvid...fg/php/enduser/std_adp.php?p_faqid=216 ) lists a "Mid-Range SLI PC Configuration" (Dual GeForce 7900 GT) as needing a 26 amp total on the +12V rail(s) for dual 7900GT cards.

Q1: Is BFG's minimum requirement for 22A on a +12V rail (and 350W total) correct?

Q2: Would a SeaSonic S12-430 ATX12V 430W power supply (14A on +12V1, 15A on +12V2, and 30A on +5V) work to power a single BFG Tech 7900GS ?

Q3: Would an Enermax Liberty ELT400AWT ATX12V 400W power supply (20A on +12V1, 20A on +12V2, and 28A on +5V) work to power a single BFG Tech 7900GS ?

Q4: Given it's Nvidia SLi Certification, what dual BFG Tech video cards could the SeaSonic S12-600 ATX12V 600W power supply (18A on +12V1, 18A on +12V2, and 30A on +5V) actually run since it doesn't meet your minimum requirements ?

Any information you can share would be enormously helpful in avoiding my purchase of an inadequate power supply for a new computer. Thank you in advance for your kind assistance.


-----Original Message-----
From: BFG Support [mailto:support@bfgtech.com]
Sent: Tuesday, October 10, 2006 12:49 PM
Subject: Re: Power Supply requirements for BFG Tech Geforce 7900GS ??

I believe the answer to all 4 of your questions is yes. The minimum requirement is for the combined amperage rating on the 12v rail.

For example, the Seasonic that has 18A on each rail would more than likely be rated at 36A overall, which would work fine with the cards. Sometimes manufacturers will certify the combined amperage different than the available amperage on each rail though, so you may want to find if that PSU is a true 36A or something lower like 30A. Either way, it should power the card fine.

Thank you,
Jeremy F
BFG Support

 

[Vaterland]

You miss the point. I am not saying that some no name 400W PSU is enough for powering X1900. I thought I made it very clear, that there is plenty PSUs out there that have just stupid design and I would never buy one like that. I am saying that a well designed 430W PSU can easily handle 7900GT. How do I know? Well, because that's what I have at home. ATI's video cards are sucking electrons like crazy, but we are talking here about 7900GS. This baby eats only 45W. Let me guess - is it about 4A on a 12V rail? Hell yeah.

 

[NoStateofMind]

Oh, that 400W PSU I was talking about....was a Fortron Source. Some think they are good, heh, won't ever see a dime of my money again.