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bunsenburner
Cinematic Immunity

join:2005-10-11
Charleston, SC
reply to Krisnatharok

Re: Very Specific Math-Based PCIe 3.0 Question

said by Krisnatharok:

That sucks man, what company made your 680?

EVGA. Things break, it happens, not to worry. They are a wonderful company to deal with. No hold time on the phone, and I mean one ring, no questions asked, very polite, and instant RMA approval. They seem to take customer satisfaction quite seriously and were sincerely apologetic about the card failure.

Asus, on the other hand...


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
I've had awesome experiences with EVGA. Did you pay for the cross-ship? It's worth it, IMO.


bunsenburner
Cinematic Immunity

join:2005-10-11
Charleston, SC
I didn't. Would have only made a few days difference. As long as Nvidia keeps designing good cards, I'll be using EVGA again.


Moos
Tequilablob
Premium
join:2008-12-11
Salt Lake City, UT
kudos:3
Reviews:
·Comcast
reply to Krisnatharok
Have you seen this article yet? If your interested in some more data and not already aware of the article, they do some pretty good non biased testing on PCIe 3.0 vs 2.0. They Test quite a few games and video card setups.

»www.hardocp.com/article/2012/07/···KE6XC2ms

Like you said, your I-7 920 is most likely bottlenecking you for the games you listed. I only say this because I experience the same thing with my 2500k. When I overclocked it to 4.4 I was able to see an FPS jump of about 10 in BF3. I run skyrim modded out at around 45 fps on a 7950 @ 2560x2440 and I also have 2 other 1080p monitors running in the background. I do have my 7950 overclocked to a modest 1100 mhz. I think the day's of an I5 being all you ever need for gaming are coming to an end, especially with games like Crysis 3, Star citizen, and The Witcher 3 on the horizon.

I have went through much of the same process your doing now for deciding on if I wanted to get the 2011 chipset vs upgrade z77. what I found was for gaming the upgrade costs did not justify the performance gains unless your planning on running 3 to 4 SLI/crossfired cards. I've elected to do nothing until Haswell comes out, but I am toying with adding a second 7950 on my current Z68 motherboard just for fun.

Another thing I have found from reading other people's tests (no testing on my own so it's somewhat opinion that I tend to agree with) is that PCIe 3.0 is approximately 2 times faster then PCIe 2.0. So basically 1 PCIe 2.0 @16x is equivalent to 1 PCIe 3.0 @ 8x. But I have not been able to see any data yet that there is a single card out there that can saturate a PCIe 2.0 @16x lane. From other peoples experiences/testing I have concluded that there does not seem to be a meaningful performance change for z77 vs x79 for gaming until you start running 3 cards in SLI/crossfire. 2 cards in SLI/crossfire seem to have negligable or very small gains in X79 setups vs z77.

If your dead set on upgrading now, my recommendation would be to grab a z77 setup and save yourself some money (unless your going to run 3 or 4 cards). I have elected to wait until Haswell myself due to the very minor upgrade in going from Sandy to Ivy. If you can hold out till Haswell it would probably be best. My bet is haswell will be out before Ivy-E (who knows if they will skip Ivy-E altogether?).

That was my thought process when looking at LGA 2011 chips anyway. I'm curious to here what other people have found too.


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
Ugh, that article is comparing two and three-way GPUs on LGA 1155, which means that the only time you get 16x lanes--on PCIe 2.0 or 3.0--is in a single card configuration.

The whole article is then wasted, by comparing mainstream chipset to mainstream chipset.

No one I know is asking if their purchasing decision is between a Z68 or Z77 motherboard. The *real* question at hand is if X79 (being able to run dual GPUs at 16x/16x) is worth the premium over Z77 (running dual GPUs at 8x/8x). The article doesn't even approach the benefit of running two GPUs at full speeds.

To put it in perspective, a Sandy Bridge build running three GPUs are going to run at 8x/8x/4x @ PCIe 2.0, which is equivalent to PCIe 3.0 lanes running at half as many lanes.

No enthusiast worth their salt is going to run high-end GPUs on such a bottlenecked board.

They really should compare x58 (16x/16x @ 2.0) to Z77 (8x/8x @ 3.0) to X79 (16x/16x @ 3.0) if they want someone to take the article seriously.
--
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety.


Moos
Tequilablob
Premium
join:2008-12-11
Salt Lake City, UT
kudos:3
Reviews:
·Comcast
Heres some more testing done with the X79 motherboards.

»www.behardware.com/art/imprimer/850/

PCIe 3.0 does have a higher transfer rate which is a no brainer. PCIe 3.0@16x transfer rate of 16GB/s vs PCIe 2.0@16x transfer rate of 8GB/s. From what I know there is not a single card that hits 8 GB/s, but I haven't seen the actual numbers. I'll see what I can find. What we need to know is the transfer rate of the 7970 (or 680).

It is noted that PCIe 3.0 uses a more complex coding system and I would imaging it's more efficient than that of PCI 2.0, which might explain the small gains of just a direct swap from 2.0 to 3.0.

I'm also intrigued in the answer if there is a noticeable gain with say a crossfire setup on X79 vs Z77.


Moos
Tequilablob
Premium
join:2008-12-11
Salt Lake City, UT
kudos:3
Reviews:
·Comcast
reply to Krisnatharok
said by Krisnatharok:

Ugh, that article is comparing two and three-way GPUs on LGA 1155, which means that the only time you get 16x lanes--on PCIe 2.0 or 3.0--is in a single card configuration.

The whole article is then wasted, by comparing mainstream chipset to mainstream chipset.

No one I know is asking if their purchasing decision is between a Z68 or Z77 motherboard. The *real* question at hand is if X79 (being able to run dual GPUs at 16x/16x) is worth the premium over Z77 (running dual GPUs at 8x/8x). The article doesn't even approach the benefit of running two GPUs at full speeds.

To put it in perspective, a Sandy Bridge build running three GPUs are going to run at 8x/8x/4x @ PCIe 2.0, which is equivalent to PCIe 3.0 lanes running at half as many lanes.

No enthusiast worth their salt is going to run high-end GPUs on such a bottlenecked board.

They really should compare x58 (16x/16x @ 2.0) to Z77 (8x/8x @ 3.0) to X79 (16x/16x @ 3.0) if they want someone to take the article seriously.

The point I took from the review is that a system with sandy bridge cpu using PCI 2.0 Is not showing signs of bottlenecking when compared to an Ivybridge using PCI 3.0 even in multi-GPU setups and eyefinity situations. I'm curious why you think there would be a performance increase by going to X79 and quadrupling the available bandwidth when doubling it with the Z77 PCI 3.0 x16 setup does not show any significant improvement? I'm sure the more expensive processor and quad channel memory will make the overall performance of the system better resulting in experience overall, but I guess i'm missing where 32 lanes of PCI 3.0 will have an effect when 16 lanes doesn't. (unless your running quad card setups with crazy high resolutions)

Those have been my thoughts on the subject and if i'm way off please fill me in with what i'm misunderstanding. I tried to find some actual data transfer rates today of what a single 7970 would pull across PCI lanes when to the point of being bogged down, but I was unable to find anything meaningful other than FPS comparisons.

On a side note, the Z68 and Z77 motherboards that specify (2 x PCIe 2.0 x16) actually do have them even though the CPU's only output a total of 16 lanesl. When running these boards in crossfire/SLI the cpu outputs 16 lanes of data with 8 lanes intended for each GPU. This data is fed into a PLX chip that spreads each set of 8 lanes into smaller packets which is sent across 16 lanes to each card. It add's some input lag into your system, but it takes care of any negative effects caused by only using 8 of the 16 lanes on the GPU. They also cost more than most boards. If a Z77 board specs say something like PCI Express 3.0 x16, then I agree it works as you explained above.


Moos
Tequilablob
Premium
join:2008-12-11
Salt Lake City, UT
kudos:3
Reviews:
·Comcast
said by Moos:

resulting in experience overall,

Grr. Proofreading never works, I don't know why I try. I men't to say "resulting in a better overall experience."