6990 slower than expected

sparx1981 · 4 Nov 2011 at 11:39

Hi guys,

Do you think an i7 870 on a 1156 board would bottleneck a 6990 & 6970 in tri-
fire?

Running Unigine benchmark I'm at 1920x1080 8xAA fullscreen I'm getting the following;

FPS:58.7
Scores:1478
Min FPS:8.8
Max FPS: 150.5

I've looked at some reviews for the 6990 on it's own and it got better results than this?

Any ideas?

Surveyor · 4 Nov 2011 at 11:42

Try it with the settings in this thread and compare your result with those in the first post.

You should be looking at a score of ~3000-3300.

sparx1981 · 4 Nov 2011 at 11:55

I got 2771....

Bearing in mind this a 6990 and a 6970 setup in cross fire it seems a little low?

sparx1981 · 4 Nov 2011 at 12:13

Just re-run and got 2929.

Marine-RX179 · 4 Nov 2011 at 12:14

sparx1981 said:
Do you think an i7 870 on a 1156 board would bottleneck a 6990 & 6970 in tri-fire?

In heaven bench? No...as that application only really test GPU capability, and CPU is not really stressed. But for real-world gaming, I would say it is likely that your i7 870 would bottleneck the 6990+6970 tri-fire, if your i7 870 is on stock clock. You should really overclock it to at least 4.0GHz.

pastymuncher · 4 Nov 2011 at 13:25

Why have tri-fire for that res anyway? It's total overkill.

Try taking the 6970 out so that the 6990 has the full 16x bandwidth of that slot instead of both running at 8x. It may or may not make some difference.

Andrew Moore · 4 Nov 2011 at 13:29

1156 has 16lanes unless the board has a chip designed to increase lanes.

So. The 6970 will use 8 lanes leaving 8 lanes for the 6990. This is not enough.

Solution...

Upgrade to a board with an additional 16lanes or upgrade your platform to 1366, 2011 (when it arrives) or BD.

1156 and 1155 are not good enough unless the board provides a facility to do so.

Stanners · 4 Nov 2011 at 14:12

Was there not a review somewhere that showed the difference between x16 and x8.

If i remember correctly it was not that a great deal?

djabs786 · 4 Nov 2011 at 14:15

Stanners said:
Was there not a review somewhere that showed the difference between x16 and x8.

If i remember correctly it was not that a great deal?

But the 6990 has to split the bandwith 4x 4x between the two GPUs inside if i recall correctly. So the 6970 has 8x bandwith and each GPU in the 6990 has 4x and 4x

Howling · 4 Nov 2011 at 14:17

Stanners said:
Was there not a review somewhere that showed the difference between x16 and x8.

If i remember correctly it was not that a great deal?

Yes, but the 6990 is a dual gpu card, so it stands to reason it uses twice the bandwidth - and in effect the single 16x lane it's running in would be 2 lots of 8x. So running Tri-Fire, it would be 8x/8x - but the gpus on the 6990 would suffer as an effective 4x/4x?

Just a theory. Too lazy to find facts to back it up, just an educated guess.

sparx1981 · 4 Nov 2011 at 14:24

My board is a P7P55D-e Pro in case that makes any difference?
I'm also about to run a Heaven benchmark again with just the 6990 on its own.

If I was to change my board? Any suggestions on what to get? Ideally I'd like to stay on 1156 if possible to save money on buying a new chip? If not.... then what are the best options?

djabs786 · 4 Nov 2011 at 14:35

sparx1981 said:
My board is a P7P55D-e Pro in case that makes any difference?
I'm also about to run a Heaven benchmark again with just the 6990 on its own.

If I was to change my board? Any suggestions on what to get? Ideally I'd like to stay on 1156 if possible to save money on buying a new chip? If not.... then what are the best options?

Personally, I'd just keep with what you've got at the moment, and wait for LGA2011 then upgrade cpu/mobo then. But that's just me, if you need mega performance now, then you could buy a new mobo and overclock your cpu

Martini1991 · 4 Nov 2011 at 14:38

Linus ran a 6990 on 16x/8x/4x and found the 8x didn't do much.
http://www.youtube.com/watch?v=rSfifE2Domo

In gaming, you'll see a difference in frames, but you'll never be in any situation where you'll be running stupidly low frames from the 8x slot.

Gerard · 4 Nov 2011 at 14:40

Martini1991 said:
Linus ran a 6990 on 16x/8x/4x and found the 8x didn't do much.
http://www.youtube.com/watch?v=rSfifE2Domo

Yup, the pci lanes dont really make a lot of difference, even at extreme res the difference is only a few fps at best. Hardocp done an article on it a while back as well.

dougie06n · 4 Nov 2011 at 14:43

i am sure i did read somewhere the 1366 i7 socket had a higher bus speed controller for pci express than 1156 i7 will try and find.

dougie06n · 4 Nov 2011 at 14:57

found the link to pci express bus speed in i7 sockets

http://www.hardwaresecrets.com/article/All-Core-i7-Models/708

Martini1991 · 4 Nov 2011 at 14:59

That i7 is on the 1156 platform, not the 1366 platform though, so it doesn't apply?

dougie06n · 4 Nov 2011 at 15:05

Martini1991 said:
That i7 is on the 1156 platform, not the 1366 platform though, so it doesn't apply?

i was just comparing as he was looking for options to change Mboard but a 1366 would be a step back he needs to wait on the 2011 socket

sparx1981 · 4 Nov 2011 at 15:13

Ok guys, to give you an update. I ran some test without the 6970 included... so just the 6990 on it's own. The difference was as follows

15 - 20 fps lower on Dirt 3. Approx 70 - 80 fps
Metro 2033 - about 10 - 15 fps lower - about 17 fps
F1 2010 - same fps.... this only ever seems to use 2 GPU's though anyway.
Heaven benchmark was a lot closer to the 2000 mark than 3000.

Interestingly... Furmark worked with just the 6990, however it doesn't run with both cards.

Finally, if 1366 is a step backwards.... what are people using to run setups like this then?

Thanks for the input guys.

Predicament · 4 Nov 2011 at 15:52

sparx1981 said:
what are people using to run setups like this then?

(Socket 1155) with a motherboard like a Asrock Fatal1ty Z68 Pro Gen 3 intel Z68 which boasts 2x PCI 16x