Bottleneck

[Doninator]

Hi folks,

I am getting ready to build a new system and have done some reading up on cpu's and video cards but I am having a heck of a time finding solid information on bottlenecks between the cpu and gpu.

My current plan is to get an i7 920 with 2 GTX 260's and 6 megs of pc 1333 ram... from what I can tell that should be a fairly balanced system. I had also considedered 2 GTX 275's instead but with the price of the 260's dropping like they are its hard to justify it unless there really is that much headroom in the i7 920.

Has anyone seen a serious article on cpu/gpu bottlenecks anywhere?

Don

 

[Atomic Rooster]

Here's an article that I posted in an earlier thread: CPU scaling with the GTX 280


For less then the cost of two GTX 216s, you could get a single GTX 285.


EDIT:

Scratch that. Looks like a GTX 260 SLI rig outperforms a GTX 285. XFX GTX285 Black Edition Review

 

[rohan23]

I'm currently running that setup. Go with the cheapest 285 you can find.

 

[Doninator]

http://www.guru3d.com/article/core-i7-multigpu-sli-crossfire-game-performance-review/19


this is one of the articles I read and it talks about an i7 765 with 3 GTX 280's and the bottleneck seems to go back and forth.. but I cannot get a 765 so this article while helpful for people with 2grand to spend on a computer is great really doesnt help me understand bottlenecks for the 920.

btw this is a great article.

note: I have a suspicion that the 920 has similiar bottlenecks but nothing that I can find has been proven that it does.

EDIT:

Scratch that. Looks like a GTX 260 SLI rig outperforms a GTX 285. XFX GTX285 Black Edition Review

Yes thats a good article.. another thing to note there is that 2 260's are as fast as a 295, the bottleneck there is the single x16 slot as opposed to two x16 slots.

There was also an article done by tomshardware about GTX275 sli vs GTX 295 in which they blew away (for the most part) the 295 and they hypothesized that it was a channel limitation and not gpu limitation. Which would make you wonder how much faster are we going to be able to go without a major architecture change from usb express to ?

for the money right now the 260's seem the way to go.

 

[rohan23]

Any processor will bottleneck such a powerful setup. Some minor overclocking with fix the problem. The i7 really shines in games with a multi card setup. But, a GTX 285 will be a better choice here.

 

[Doninator]

rohan are you suggesting going with 1 GTX 285 then 2 260's if so why? when testing shows 260 sli is faster than a single 285 or a 295?

If I had unlimited money I would most definetly go with 2x285's but thats not the case.

In the article above it shows that the i7 265 did bottleneck at 2560x1200 settings with 3 GTX 280's.

personally I think that if you OC the 920 to about 3.8-4ghz that it would perform similiar to the 965.

maybe some day one of these companies that put out articles will adress this issue and show bottlenecks for all of the processors and then builders/home builder will know the optimum builds for their systems.

Don

 

[rohan23]

What resolution are you running? What power supply do you have?

 

[Doninator]

well I havent built it yet.. I am just tryin to figure stuff out.

I plan on running 1920x1080

power supply will be based on what I build.

 

[Atomic Rooster]

The GTX 260 SLI setup outperforms a single GTX 285 on resolutions from 1280x1024 on up. They easily outpace even an overclocked GTX 285 @ 1900x1200 in the review posted.

 

[sniperviper21]

basically, any 2 current gen cards in sli will outperform a single card