Crossfire 390x with 2600k @ 4.5 or Dual Xeon 2670s?

[controlflow]

So I decided to build a new system for fun. My current system is as follows:

2600k @ 4.5 Ghz
16 GB DDR3 1600
HD 7950
Asrock Z68 Motherboard
Antec 620 Watt PSU

This system is hooked up to 3 mediocre 1080p panels but I can really only run modern games at 1080p on a single monitor. I plan to preserve this system even though I am building the new one.


New system that I am building:

Dual Xeon E5-2670
64 GB Registered ECC DDR3 1600 Quad Channel
Asrock EP2C602 Motherboard
EVGA SuperNOVA G2 1300 Watt
Crossfire XFX R9 390x 8GB
Samsung 850 Pro 500 GB


The new system will be used for SW dev, running VMs, server applications, image and video editing and finally gaming.

I have 2 questions:

• Which CPU will do better for gaming, the 2600k@ 4.5 or the pair of 2670s? I've been out of the tech scene for a bit so not sure if games are more multi threaded these days or if DX12 has really reduced CPU overhead.
  
• Would you rather go with a 1440p display or 4k for this system? Are two 390xs enough for 4k gaming for now and into the foreseeable future? It would be unpleasant to get a 4k panel only to be forced to run it at a lower non native resolution later. I'm hoping I can get away with a 4k panel since I would love it for image editing.

 

[NTMBK]

I'm a bit torn... the CPU performance of the 2600k will be better on older games/single thread heavy games, the Xeons might be better on newer multithreaded games. Plus the Xeons have way more PCIe bandwidth- 40x PCIe 3 per socket, vs. 16x PCIe 2.0. That means each GPU will have 4 times as much PCIe bandwidth, and given that the 390X performs Crossfire over PCIe that could make a big difference.

Sounds like a good comparison article

 

[redzo]

out of the tech scene for a bit so not sure if games are more multi threaded these days or if DX12 has really reduced CPU overhead.

The low clocks of those xeons are definitely party poopers as far as gaming performance is concerned. Games should run just fine on them, but don't ask too much and don't get too picky with the fps.
Games still love high clock cores -> so they run best on the latest uarch: 6700k skylake.
https://www.youtube.com/watch?v=ocwwaVGUFtk

 

[Denithor]

Exactly what I was going to say, the lower clockspeed of the Xeon chips means they won't be able to feed the GPU(s) as well as the 2600K will. This may change with DX12 but it will likely be years before this becomes widespread in usage.

 

[controlflow]

Thanks for the responses guys. It looks like the 2600k should have the advantage then, but I do wonder how much the lack of PCIe bandwidth on that older platform will hurt the crossfire setup.

I think I'll first set everything up on the Xeon system and if I find the gaming performance to be poor, I'll try the 2600k. My gut feeling is the 2670s will will have enough grunt to push out smooth frame rates. I'm also thinking that at a high resolution like 4k, the bottleneck should shift mostly to the GPUs.

Would you guys recommend 4k or 1440p for a crossfire 390x setup?

Pretty amazing how well these processors have aged. Long live the venerable Sandy Bridge core

 

[Denithor]

Dual 390X should be good for 4k, at least today. Tomorrow's games may change that, just have to wait and see.

Also, you are aware the next generation cards are due to drop within the next 2-3 months, right? If you haven't already bought those 390's you might want to wait...

 

[controlflow]

Dual 390X should be good for 4k, at least today. Tomorrow's games may change that, just have to wait and see.

Also, you are aware the next generation cards are due to drop within the next 2-3 months, right? If you haven't already bought those 390's you might want to wait...

Have not purchased the 390s yet. I did know both Nvidia and AMD were coming out with new GPUs but doesn't it take a few more months for the higher end stuff to come out?

2 390xs can be had for under 700 now and offer a good deal of more performance than a single 980 Ti. Would $700 buy significantly more performance when the new cards come out? If so I suppose I can stick to the HD 7950 and 1080p for a few more months.

 

[Headfoot]

Wait for the next gen cards. Even if you don't, don't get 2x 390x. Even though it is theoretically faster than a 980 Ti, that's only when crossfire works properly. I have 290 CF and at the same price point I'd take an aftermarket 980 Ti overclocked every day of the week. I'd only do Hawaii x2 if you can get it at a significant discount from the 980 Ti. Too many modern games are not AFR friendly, and if they do get CF/SLI support its usually a good while after it comes out. The older, AFR friendly games you can usually run at max on 1 390x anyways.

CPU wise, you'd probably be best served with a 5960x with watercooling, overclocked to 4.4 or more if you can manage it. You get the huge cache and 8 cores of the Xeon, but you're still running on a fast architecture (though, not as fast as Skylake by just a small margin) and you don't have to give up clock speed. The downside is its super expensive. The 5820k is a great alternative, a lot less expensive, you lose 2 cores but they also usually overclock better and you're still at 6 cores for the multi-thread friendly productivity apps you're using.

 

[controlflow]

Wait for the next gen cards. Even if you don't, don't get 2x 390x. Even though it is theoretically faster than a 980 Ti, that's only when crossfire works properly. I have 290 CF and at the same price point I'd take an aftermarket 980 Ti overclocked every day of the week. I'd only do Hawaii x2 if you can get it at a significant discount from the 980 Ti. Too many modern games are not AFR friendly, and if they do get CF/SLI support its usually a good while after it comes out. The older, AFR friendly games you can usually run at max on 1 390x anyways.

CPU wise, you'd probably be best served with a 5960x with watercooling, overclocked to 4.4 or more if you can manage it. You get the huge cache and 8 cores of the Xeon, but you're still running on a fast architecture (though, not as fast as Skylake by just a small margin) and you don't have to give up clock speed. The downside is its super expensive. The 5820k is a great alternative, a lot less expensive, you lose 2 cores but they also usually overclock better and you're still at 6 cores for the multi-thread friendly productivity apps you're using.

hmm, ok I guess I will wait on the graphic cards. Hopefully the next gen stuff does not disappoint. If nothing else, at least the power efficiency should improve massively going to 14-16 nm and finfet.

As for the CPU and rest of the platform, this Xeon thing I'm building is just kind of for fun since this stuff is all dirt cheap now and I'll use it for home server and number crunching purposes. I think I will wait for Skylake-EP to replace my 2600k machine and will pick up whatever replaces the 5960x. I'm thinking the pair of Xeon 2670s and the 2600k should be enough to handle any games this year.

 

[Headfoot]

Broadwell E is supposed to have 10 cores as the top chip, so the second from the top should be an 8 core chip and likely wont be $1000 like the current 5960x, so that might be worth watching for. I don't know what the rumored release date is though.

A 2600k at ~4.6 definitely still holds fairly solidly. While HT has gotten better with Haswell and even better yet on Skylake, it still helps on 2600k for games that use more than 4 cores.