GTX 570 sli vs GTX 580 sli? Which makes more sense?

if i were you the better price vs performance, i'll go with the 2x 6950 unlock it to 6970 which beats 570 sli in almost all games(sometimes beats the 580sli depends on the resolution) for lower price/less heat/less watts and save about $420 , the unlock rate is very very high.

What is your system and resolution? Spending the cutting edge costs of the 580 might not give you any real benefit if your system or resolution can't support it.

The various Guru3D articles are summarized here:

Card 570 580 570 SLI 580 SLI 6950 6970 6950 X-fire 6970 X-fire

Guru3D
COD-MW 148 168 230 265 127 140 150 165
Bad Company 2 56 67 103 108 50 56 96 108
Dirt 2 80 96 138 149 72 77 131 140
Far Cry 2 85 104 153 164 76 83 147 161
Metro 2033 27 33 54 65 25 28 50 56
Dawn of Discovery 74 86 109 112 78 85 90 98
Crysis Warhead 54 62 86 90 51 57 87 97
Total 524 616 873 953 479 526 751 825

Total FPS single card / SLI Xfire

570 - 524/873
580 - 616/953
6950 - 479/751
6970 - 526/825

$ per frame single card / SLI - Xfire

570 - $0.67 /$0.80
580 - $0.83 /$1.07
6950 - $0.63 /$0.80
6970 - $0.72 /$0.92

Hardware Heaven's results on the 570, 580 and 6870 went

Alien Vs Predator 45 54 56
Bad Company 2 68 73 62
COD -BO 105 110 96
Crysis Warhead 44 46 40
Civilization 5 101 111 100
Formula 1 59 64 60
Mafia 2 81 87 101
Medal of Honor 124 130 109
HAWX 2 145 166 67
Left For Dead 2 54 56 53

Summary Total fps

570 - 826.0
580 - 897.0
6870 - 744.0

Taking out HAWX which had a huge disparity ...

570 - 681.0
580 - 731.0
6870 - 677.0

BenchmarkReviews fps summary went

570 - 346.2
580 - 400.3
6870 - 300.4

Summary of all 3 tests, fps summary

Summary

570 - 1696.2
580 - 1913.3
6970 - 1570.4

Cost per frame is:

570 - $0.21
580 - $0.27
6970 - $0.24
6950 flashed to a 6870 - $0.19

If ya gonna do the flashie thing, do it fast ... I can't see ATI taking the financial beating for too long on this one.

All in all, the 570 and 6870 are the two most closely matched cards I have seen from ATI and nVidia. There's a bit of an edge on SLI over X-fire however based upon the tests above in the 570's favor:

Scaling % for the 570 is 166.60%
Scaling % for the 580 is 154.71%
Scaling % for the 6850/70 is 156.78%

Monitor resolution?

Should make correction: 6870 should be 6870 bad tipping in all my guess

There are a several issues to consider on the 570 vs. 580 SLI issue:
1) Cost
2) CPU bottlenecking - is always higher on higher performing cards, and reduces the scaling factor of dual card setups to yield diminishing returns with higher performing cards.
3) Heat and noise - Fortunately, Nvidia seems to have figured this one out with new vapor chamber cooling and redesigned shrouds that allow better intake airlflow and airflow between cards.

This should be a little more clear to read:
http://www.guru3d.com/article/radeon-hd-6950-crossfirex...
http://www.guru3d.com/article/geforce-gtx-560-ti-sli-re...
http://www.guru3d.com/article/geforce-gtx-570-sli-revie...
http://www.guru3d.com/article/geforce-gtx-580-sli-revie...
http://www.guru3d.com/article/asus-gtx580-directcu-ii-s...

Average dual card scaling across all benchmarks at 1920x1200:
6950: 1.67x
560: 1.69x
570: 1.7x
580: 1.58x
Asus 580: 1.51x

Noise levels (vs. single card)
6950: 49 Dba (+8 Dba)
560: 40 Dba (+3 Dba)
570: 42 Dba (+2 Dba)
580: 46 Dba (+5 Dba)
Asus 580: 42 Dba (+3 Dba)

GPU Temps (vs. single card)
6950: 89c (+12c)
560: 74c (+6c)
570: 81c (+4c)
580: 90c (+3c)
Asus 580: 73c (+7c)

In all, i would go with the GTX 570's in SLI, unless you have a REALLY high-end system and need absolutely the best. A 3D Vision Surround setup, for example, would definitely lean towards getting the best you can afford. Besides, being cheaper, the 570's will also yield better scaling to close the performance gap somewhat with the 580's.

Those reviews don't crank up the details full tilt for the most part. 580s will accommodate the 32xCSAA, 8x AA transparency (thanks for this tip matto17secs!) and the 16xAF with high tesselation settings. When you start getting into the details and then throw in higher resolutions, the 580s are the way to go in SLI.

I run them with an i7-930 with no OC. The regularly reach up 99% GPU load (measured through GPU-z) at times during BFBC2 sessions. They would not reach this level of utilization if there were a bottleneck.

If you want the best-newest-fastest card (cost not a consideration), there is no question.

This topic has been closed by Mousemonkey