breaking 2.6 on opteron 175

[m1ldslide1]

So I had been running my opteron at:
260x10 @333 divider 1.45vcore 2.8vdimm
Decided to try for more, and dropped to the 266 divider and got these results:
Max HTT: 345x7 = 2.4ghz
Matt 8x: 320 = 2560 (running dual prime right now for about 30mins, so far so good)
Max 9x: 285 = 2565

I'm assuming that 10x max with this divider will still be about 260, and that's what I can get at 333, so I didn't test it.

Any other ideas? I haven't tried raising my vcore above 1.45, and right now I'm under full load at 46C. I tried raising my vdimm up to 2.9 but it didn't seem to make any difference.

It just bugs me that I can get around 240 HTT at 1:1 but can't turn that into a very stellar overclock. It sure would be awesome if I could even squeeze 2.7ghz with a 9x multi and 300mhz HTT at the 266 divider. That's what I was hoping for anyway.

Any feedback would be much appreciated!

 

[cubeless]

just do the drill in the guide at the top of the forum...

sometimes u don't get an over the top oc...

 

[m1ldslide1]

Originally posted by: cubeless
just do the drill in the guide at the top of the forum...

sometimes u don't get an over the top oc...

The ceilings I'm reaching were achieved using zebo's guide.

My question is if anybody with great opty overclocks can tell me if I'm overlooking anything or any possible combination that might help.

 

[aka1nas]

If you drop the RAM speed further and/or loosen timings , are you able to hit higher clocks? You may have some sub-timings that are set too aggressively. The downside of the IMC is that it tends to become more finicky when you OC the CPU further.

Another thing to think about is that many boards set timings based on SPD values, but will assume that they are running at the Divider you selected. I.E. if you are running at the 133Mhz(266DDR) divider and your RAM has SPD settings for that speed, the board may take those settings even if they are not stable at the actual speed you are running the RAM at. Most RAM sticks will have their SPD programmed with a range of timings that get tighter as you decrease RAM clockspeed.

 

[m1ldslide1]

Originally posted by: aka1nas
If you drop the RAM speed further and/or loosen timings , are you able to hit higher clocks? You may have some sub-timings that are set too aggressively. The downside of the IMC is that it tends to become more finicky when you OC the CPU further.

Another thing to think about is that many boards set timings based on SPD values, but will assume that they are running at the Divider you selected. I.E. if you are running at the 133Mhz(266DDR) divider and your RAM has SPD settings for that speed, the board may take those settings even if they are not stable at the actual speed you are running the RAM at. Most RAM sticks will have their SPD programmed with a range of timings that get tighter as you decrease RAM clockspeed.

I've set my timings to 3-4-4-8 1T, but there are over a dozen other sub-timings that were set by SPD. Unfortunately there's no documentation that I can find that talks about what other options I have for setting these, and I don't have the time to change one, run prime, so on and so forth.

How do you DFI-expert guys get by? - I'd be pulling my hair out wondering what all of those settings mean and whether or not I'm hosing the whole thing with one misplaced setting.

 

[cubeless]

use a64tweaker to see what the settings are that the 'auto' settings are giving u... set them all (as many as u can) in the bios... then start loosening up a bit...

ran into just this issue (using 133 div and auto and getting spd values that were too tight) on the k8n from geeks... this was using 4 stix of mem... didn't have the problem with my lanparty, but i started at 166 with just 2 stix of mem...

 

[myocardia]

Originally posted by: m1ldslide1
I've set my timings to 3-4-4-8 1T, but there are over a dozen other sub-timings that were set by SPD. Unfortunately there's no documentation that I can find that talks about what other options I have for setting these, and I don't have the time to change one, run prime, so on and so forth.

How do you DFI-expert guys get by? - I'd be pulling my hair out wondering what all of those settings mean and whether or not I'm hosing the whole thing with one misplaced setting.

Those of us with DFI boards have at least 30 different settings for our RAM. That's why all of the noobs that buy a DFI board are always completely lost, and swear that they don't overclock well. Also, most people who've bought Opteron 175's say they'll only do ~2.6 Ghz. What stepping is your 175? That makes a difference.

Anyway, you should set your tRC and tRFC to Auto at first, and your tREF to 1560. If Auto doesn't work like it should, then try tRC=14 or 15, and tRFC=17 or 18, and keep your tREF at 1560. If your BIOS doesn't have any of those settings, it's because it handles them automatically, and there's nothing you can do about that.

 

[11427]

Dunno,...DFI's are a piece of cake,.... you just need to do a little research is all. And a good forum like DFI Street/DIY Street is very helpful. Maybe there is a good dedicated forum for your Abit out there somewhere.

 

[SparkyJJO]

When I OC'd my opty 165 I got stuck at 2.5GHz, no matter what I set the RAM primary timings to or the divider. I found later there is a couple secondary subtimings that when I loosened them a little I could go much higher (hit 3GHz but temps got too high for my air cooler to handle). I forget what the timings are though, asynchronous latency was one of them and I forget the other.

 

[m1ldslide1]

Originally posted by: myocardia

Originally posted by: m1ldslide1
I've set my timings to 3-4-4-8 1T, but there are over a dozen other sub-timings that were set by SPD. Unfortunately there's no documentation that I can find that talks about what other options I have for setting these, and I don't have the time to change one, run prime, so on and so forth.

How do you DFI-expert guys get by? - I'd be pulling my hair out wondering what all of those settings mean and whether or not I'm hosing the whole thing with one misplaced setting.

Those of us with DFI boards have at least 30 different settings for our RAM. That's why all of the noobs that buy a DFI board are always completely lost, and swear that they don't overclock well. Also, most people who've bought Opteron 175's say they'll only do ~2.6 Ghz. What stepping is your 175? That makes a difference.

Anyway, you should set your tRC and tRFC to Auto at first, and your tREF to 1560. If Auto doesn't work like it should, then try tRC=14 or 15, and tRFC=17 or 18, and keep your tREF at 1560. If your BIOS doesn't have any of those settings, it's because it handles them automatically, and there's nothing you can do about that.

Hey thanks for the suggestion myocardia - I'll try out those settings when I get home to my PC. I'm not sure off the top of my head which of those are visible and which aren't, but I'll have a look-see.

 

[secretanchitman]

my opteron 170 does 2.65Ghz, 1.30vcore, 2.65vmem.

try doing 166 on the memory divider and up your voltage to 1.45v...your ram timings shouldnt matter i dont think (should be on the tightest). btw, do you have PC4000 ram or PC3200?

 

[DrMrLordX]

The real question on my mind is, how far can you push your CPU using the 2:1 (DDR200) divider?

 

[Antikristuseke]

Slap on some more voltage, with 1.55 i have my opty 165 benchstable at 9x345, though you just might have a bad steping

 

[cubeless]

Originally posted by: Antikristuseke
Slap on some more voltage, with 1.55 i have my opty 165 benchstable at 9x345, though you just might have a bad steping

your statement and sig differ...

and methinks that @ 1.55 the chip is a firework waiting to go off...

 

[Antikristuseke]

1.55 is quite safe with decent cooling thouhg i wouldnt run any more than that for 24/7 use, if my motherboard owuld allow id bench with 1.6 and more if i had water. The link in my sig shows highest benchstable, the info under it is 24/7 stable.

 

[m1ldslide1]

I was at the GF's last night so I didn't get a chance to try anything yet.

I don't think I'm going to raise my vcore any higher than 1.45, especially since people get such great overclocks at far lower. I am however going to see what I can get my HTT to at the 200 divider, and what I can do about my latency timings. I'll post back once I have some results...

Thanks for the input.

 

[aka1nas]

Generally speaking, you won't get much more if anything out of the chip using above 1.5v on a K8 unless you are on phase. More commonly on air, you will get worse results due to the extra heat generated.

 

[aigomorla]

Originally posted by: m1ldslide1
I was at the GF's last night so I didn't get a chance to try anything yet.

I don't think I'm going to raise my vcore any higher than 1.45, especially since people get such great overclocks at far lower. I am however going to see what I can get my HTT to at the 200 divider, and what I can do about my latency timings. I'll post back once I have some results...

Thanks for the input.

omg heavens no!!! not if your on air.

Also, do you happen to know your steppings? My old opty was legendary.

I'll eat an FX-62

the funny thing about her however was she didnt like voltage in the range of 1.4-1.5!

I would try to lower your voltage to 1.375

Also up your voltage on your chipset by .1-.2 i found out this usually helps.

And lastly make sure you dont pass 1000mhz HTT. i found out having it over 1000mhz, your fsbxltd , your system gets awefully unstable.


You also mentioned your running a DFI expert. Did you plug in the extra power plug on the board? It should of looked like a floppy plug right on top of your first PCI-E slot. That helps a lot on stability.

 

[ajemm]

Originally posted by: aigomorla


I'll eat an FX-62

I get jealous every time see this. It takes me 1.5v to get to a shaky 2.6GHz.

 

[m1ldslide1]

OK so I finally got after it tonight:

I tried lowering my voltage to 1.35, and was unstable at 8x325 ddr266. Raised it back to 1.45 and stable.

6x multiplier at ddr200 gets me up to 380 HTT, at least for 5 mins stable with dual instances of prime. I didn't try a 7 multiplier, which would get me 2660. Before I deal with a whole bunch more CMOS resets trying to dial in a x7 multi at ddr200 I was wondering if I'm going to have a performance hit for having such an aggressive divider.

In other words, does a 2:1 divider outweigh the 3% benefit I would get by maybe reaching 2.65 or 2.7ghz? Or does it not matter since A64 has the on-die memory controller?

Also in my bios the only memory timings available besides cas/trcd/trp/tras are:
tRRD = 2
tWR = 3
tWTR = 2
tRTW = 3
(Values are set by SPD)

If anyone has any clue about these then I'm all ears.

 

[myocardia]

You should leave those subtimings alone, at least as far as I know. They aren't like tRC, tRFC, and tREF. So, you never did say whether or not you have PC3200 or PC4000 RAM. Which is it? Anyway, it looks like you've just got a 2.6 Ghz Opty 175, like the majority of people who've bought one.

 

[m1ldslide1]

My RAM is pc3200, and rated at 2-3-2-5 stock. When I installed the opty I found that I was able to get up around 240mhz HTT at 1.45vcore and 2.8vdimm at 3-4-4-8. Once I settle on a CPU speed I'll try to tighten the timings up some.

I am interested to hear though if the 2:1 divider will impact performance any, especially compard to the extra 50-100 mhz I would maybe be able to squeeze out.

 

[DrMrLordX]

The 2:1 divider will kill your performance in most cases. The question was: how far could your htt and CPU be pushed with RAM removed as a limiting factor? It seems like you can reach the 370 htt without issue (seeing as how 380 was unstable). Now what I'm wondering is, how far will the CPU go under these circumstances?

This is the essence of isolation and consolidation (as per Zebo's thread). If you've already done this, feel free to upbraid me for redundancy . . . but from your initial post, that does not seem to be the case.

 

[myocardia]

Why in the world are you running a memory divider at all? Your RAM will have no problems running 1:1 (no divider), if you would use the 11x cpu multi, and it will do it with 3-3-3-7 or 3-4-3-7 timings. 11x236=2.6 Ghz. You'll be able to use the 180 Mhz divider, no matter how high your cpu is able to go, if your motherboard has that divider. If it doesn't, you'll never need to go lower than the 166 divider.