780i vs X38 - Which to choose?

[DarkRogue]

Hello,

I'm posting all over the place because I have so many questions about everything but please forgive me. My current PC - my last build - was put together 5 years ago, so my knowledge kind of ended there. I'm going to upgrade and build a new rig soon so I've gotta get back into the swing of things.

My target CPU is the E8400 Wolfdale that's slated to come out next week. Now I need a good mobo to go with it. The first step is to pick a chipset, I believe. My PC is using an old nForce2 chipset (Asus A7N8X Deluxe) and it works very well and is very reliable, so I was waiting for the 780i to come out. It did come out, and I was about to put it on my list, except I'm not entirely sure I need the 780i. I am a gamer, and I want to try my hand at a little basic overclocking just to get my feet wet, but I'm not going to be running SLI, much less "Triple SLI" that the 780i is boasting, so it seems much of what the 780i offers is going right out the window. Barring multiple graphics cards, what are the differences between the 780i and the X38 (and to a lesser extent, the P35) which appear to be the most popular chipsets currently?

I did a quick check of prices on newegg and it appears the only 780i boards out right now are 320, the X38 boards are around 200 and the P35 boards are anywhere from 100-200.

Price IS a concern as I'm trying to build within a budget but if the value/price is reasonable, I'll go for it.

FWIW I'm thinking of targetting a 400MHz FSB on both the CPU and RAM to maximize efficiency.

Thanks in advance

 

[Heidfirst]

sounds like a P35 would suit you fine tbh.
Or if you really think that you need PCI-E 2.0 wit a few months for P45.

If you don't need SLI stick with an Intel chipset, they are better.

 

[Cheex]

Seriously...Honestly...Just pick any P35 board you like and you'll be all set.

 

[DSF]

Just want to provide more support for the P35 choice. X38 isn't going to provide any tangible benefit to you.

 

[DarkRogue]

What exactly is the benefit of X38 over P35? Is PCIe 2.0 the only difference? I'll likely be using this new rig for another 5 years or so, so I want to future-proof it a little bit. I remember I built my current rig, and then AGP promptly went out the window so I couldnt upgrade my video card anymore. :/

I do agree that buying a 780i without using SLI is a waste, and if it doesn't offer anything else over the Intel chipsets, I may as well go with an Intel one since I'll be pairing it with an Intel processor.

 

[Jevon]

I agree with P35 over X38 according to your first post.

In regards to your second post, the X38 boards only provide a few things over P35s:

SOME X38's support DDR3, which I defnately don't recommend for you
X38's have PCI-E 2.0 slot
X38's have at least two (some have four) PCI-E full speed 16x electrical slots

The last point is the post important. P35 boards have a single PCI-E slot running at full 'speed' of 16x (also referred to as 16x bandwidth or electrical), and P35 boards you see that support Crossfire will have two PCI-E 16x slots...however, only ONE of those slots will run at full 'speed' of 16x electrical - the second PCI-E slot will only run usually at 4x speed/electrical, which hurts performance even on 3850's in Crossfire.

X38 boards can have PCI-E slots (two or four of them, depending on the board) that each run at full 16x electrical/speed. I know it's confusing as hell because they're all advertised as PCI-E 16x slots, but only some actually run at full 16x speeds! Usually under the product specs under 'Expansion Slots' you will see the details of the PCI-E slots; some places will say they run at 16x, or are in full 16x mode, some even properly call it electrical, but you gotta check this area out unfortunately every time to be sure.

Now, you only need to worry about any of that if at some point down the road you wish to Crossfire (you can only SLI on nVidia's motherboards, not P35's or X38's). I like Crossfire, I think it's improved vastly over the Crossfire of the past, so mayeb you should consider this: Get a 3870 card now on an X38, and then in a year or two when the card is slowing the system down, add a second one as they'll be cheaper and drivers will be even better than they are now. You could also do this with the soon to be released 3870x2 cards, get one now, add a second later. To me this is a great way to extend a system's life, you may want to google around for some 3870 Crossfire reviews. Or even 3850, two of those in Crossfire are pretty much the same a GTX, and cheaper

Hope that makes a little bit of sense anyway, cheers!

 

[Heidfirst]

Originally posted by: DarkRogue
I'll likely be using this new rig for another 5 years or so, so I want to future-proof it a little bit.

we'll all be using a different socket & RAM by then ...

 

[The-Noid]

Computers just arn't going to be up to date for 5 years. You best bet is to spend less and upgrade along the way.

 

[DarkRogue]

Very informative post, Jevon.
You also brought up a good point I hadn't even considered, about using the Crossfre ability as an upgrade. I think the 8800GT is the best deal for the moment though, so if I were to go that route and add another card as an upgrade later on, it would have to be a second 8800GT and therefore, SLI.
I think by that time though, there will be another single card option out that will probably outperform 2 8800GT's in SLI and depending on the price, may be a better alternative. That would effectively negate the usefulness again of buying an SLI board..

I know Nehalem and a new socket type is around the corner and DDR3 is already out.
I'm thinking of getting the E8400 because it seems like it will be a good CPU to last me until the next time I upgrade which will probably be when Nehalem's die shrink comes out.
DDR3 is still way too expensive so I haven't been able to consider it.

It won't stay up to date for 5 years, but I do want to make sure I can keep my video card up to date, meaning hopefully PCIe won't bite the dust anytime soon, and in the case of the P35, that the PCIe 1.0 doesn't get overwhelmed in the next 3-4 years (partly why I was looking at PCIe 2.0, for added headroom in case things catch up.)

 

[Jevon]

Yeah, Nehalem is going to be a big socket change again. Basically I think if you did decide to go with the X38/Crossfire option for the long-run, the idea would be to buy into the 2nd gen Nehalem releases once the new socket motherboards have been worn in.

In the past it's always been the easiest and hassle free way to use singel cards vs Crossfire/SLI, but now with how well Crossfire is performing I've been leaning towards it. Also, both ATi and nVidia have been saying the focus is on creating multi-card setups and muti-GPU's on a single card, so it makes me wonder how long we're going to have to wait for a new 'GTX' single card performer.

I'm looking to build in the next couple of weeks, I think I'm going X38 (Asus P5E) with a 3870x2 (one card, two graphic processors on it). We don't have benchmarks yet, so that's what I'm waiting on but considering how the 3870 performs I'm sure that one 3870x2 will be a terrific card for the time being. Then, I'll plop in another one maybe during one of the sales next winter (Black Friday, Boxing Week) since the regular price should be down by then already too. That should last me until Nehalem motherboards are solid and DDR3 affordable/sensible

If you choose to go with a P35 and a single card don't worry too much about the PCI-E 1.0 slot. No card is going to need the full bandwidth/speed/electrical, the only thing you'll need to make sure you have is a quality PSU with the extra GPU connector since the 1.0 PCI-E slots can't feed as much power to the card by itself. It's pretty standard these days to have these connectors (or at least the pin converters) included with the PSU package.

You should be all set to rock and roll either way!

 

[DarkRogue]

Okay, well I was thinking of X38 to avoid missing out on anything, but it seems I won't be missing out on much. Regarding the P35's, are they officially compatible with the new 45nm processors? I remember reading about certain boards having problems with them, and I want to avoid that if possible.

 

[Jevon]

I'm not sure we'll hear much more about compatibility officially until the 45nm are on the market. I'd guess your best bet right now is to make a short list of the P35's you're interesting in and check out the official support forums their respective companies have. Hopefully there will be some Q/A's or FAQ's already asked there with some semi-official responses.

Otherwise, the guys over @ xtremesystems.org/forums are going over the few Engineering Sample and Retail 45nm chips that have been acquired so far so you might be able to find compatibility info there.

I'm fairly confident that almost all P35s should work well with the 45nm because the P35's have a bus speed of 1333mhz, which is what the 45nm like. But like I said, I don't think we have any official lists of supported boards just yet. If anyone has one though I'd love to see it

 

[DarkRogue]

Wait, about that bus speed, is that the maximum?
I want to push the CPU's FSB up to 400 to match the speed of the ram, and that means the CPU FSB will effectively be 1600.. Can the P35's handle that?

 

[bigsnyder]

The new GA-EP35-DS3 series boards claim to support FSB-1600.
Link for GA-EP35-DS3P

 

[cdfire]

Originally posted by: bigsnyder
The new GA-EP35-DS3 series boards claim to support FSB-1600.
Link for GA-EP35-DS3P

Just read the thread on the GA-N680SLI-DQ6 and you will see that Gigabytes claims don't mean jack.

 

[DarkRogue]

I'm not entirely sure what the numbers mean.

I notice most boards (at least for P35) say they support 800/1066/1333 FSBs, but are they talking about DDR2 speeds, or CPU speeds? Or does that distinction even matter?

Can I not overclock to 400FSB (1600 CPU - 800 DDR) with a mobo that doesn't support 1600?

I'm trying to understand what I'm looking for exactly.

 

[bigsnyder]

Yes you can. Most P35 boards easily hit 400Mhz (1600 quad bumped which is the number often specified for fsb speed),
with a 1:1 memory ratio, that would also be 400Mhz (DDR2-800 speed). As far as boards saying they support 800/1066/1333
fsbs, they are saying it supports CPUs which interface at that speed. I hope that helps clarifies the numbers.

 

[DarkRogue]

So in other words, that means I do not need a mobo that specifically states 1600FSB support in order to use 1600FSB, as long as it supports DDR2 800?
What's the advantage of getting one then? Just for the assurance of knowing it will be completely stable at 1600?

 

[bigsnyder]

Pretty much yes, though a board doesn't necessarily have to state DDR2-800 support
(though most anymore do) in order to run those speeds. The only "advantage" for a
1600FSB supported board is compatability for official 1600FSB cpus. Remember any
non-1600FSB cpu running that speed is an overclock and stability will not be guaranteed.

 

[DarkRogue]

I see, thanks for clearing that up, I was getting incredibly confused.

So the upcoming Wolfdales are slated at 1333Mhz FSB, so any mobo rated for 1333MHz FSB should do, and both should be able to handle the overclock up to 1600. However, if I want to be a little safer I can look for mobos that support 1600 so that any instability will be the fault of the CPU and not the mobo. Does that sound like a viable plan?

It seems the decision is not even listed in the topic anymore lol. I think I'm fairly convinced that I can go with a P35 and stick with that for another 5 years or so. Although an X38 would allow me to upgrade to DDR3 some time in the future.. but I dunno. 780i is wholly wasted if I don't use SLI at all.

 

[Heidfirst]

Originally posted by: DarkRogueAlthough an X38 would allow me to upgrade to DDR3 some time in the future..

only if you get 1 that has both DDR2 & DDR3 slots & there aren't too many of those (typically mobos designed for only 1 type of RAM are better optimised than those that have to straddle 2).
& if you want to go that way there are a couple of "combo" P35s too.

 

[DarkRogue]

Good point - I forgot DDR3 modules were slightly different.

I'm not sure if I'd go for those combo boards if what you say about performance being hindered is true. I'd rather full speed DDR2 than half speed DDR2+DDR3 so to speak.
I suppose I'll hold off on DDR3 as well then, get it when DDR4 is around the corner and DDR3 prices have bottomed out lol.