PCI-E Slot 1&3 (16x/8x) instead of 1&2(16x/16x) Question

Antx777 · 28 Aug 2010 at 20:33

Hello,

Took delivery of OCuk pre-built system this week http://www.overclockers.co.uk/showproduct.php?prodid=FS-143-OE, and configured with 2 GTX480' in sli. the cards actually arrived in the box - not the system. Anyway, I thought i would do the normal thing, plug them in the blue slots (Asus P6X58D-E Intel X58 (Socket 1366) DDR3 Motherboard)

Now I have a Emu-0404 sound card that was in my last system, and in order to get this in, i obviously have to go Slot 1&3 with the GTX's. What i want to know is: how much performance loss will i get using the 16X/8X config (not sure whether you can change the lanes on the third slot to 16x)

I tried it anyway. What i got was this in Vantage:

39,550 (p score) 33,569 (GPU) in 16x/16x mode
38,987 (p score) 33023 (GPU) in 16x/8x mode

Didn't have many games to try (will do some tonight though with crysis1/warhead/Bfbc/metro etc) but would i be "OK" using the 16/8 format? in order to get my EMU-0404 sound card in (thats for music production) Only other option is to get a USB version of the card.... but that £160

TIA for replies

EDIT my initial impressions are that i won't lose too much ground using the 16/8 format, what do you guys think?

Ant

CaptainRAVE · 28 Aug 2010 at 20:35

Nothing wrong with using 16/8. You will get little performance loss - probably nothing noticable.

PhillyDee · 28 Aug 2010 at 20:36

Its only a benchmark, and varies very little. If it works, and you are happy with the gaming performance, then do it that way.

They cannot come installed, as they might have damaged the PC, modern cards are quite heavy and liable to sustain damage when thrown around and dropped by the delivery companies.

RavenXXX2 · 28 Aug 2010 at 20:36

Perfectly fine, the performance difference between PCI-E 2.0 16x v 8x is negligible going by tests that have been done.

Antx777 · 28 Aug 2010 at 21:07

Thanks for the replies. I though "8" being half of 16 would give me similar results in games

Yes Phillydee, i understand that about not installing the cards (though my last system from Okuk had my GTX8800's IN which are EXACTLY the same "length" as the 480's I measured them tonight. It was the "fitted" cooler wobbling-about that i thought would be worrying for OcUK to send out, seeing that they don't fit them on overclockerd Bundles (not systems).

Thanks

Ant

johny dolan · 28 Aug 2010 at 21:24

I have a 5970 in the x16 and a 5870 in the x8 tested the other day the 5870 in slot x16 and got same score in AVP.

Running the 5870 in the x8 gives more room between the cards and i can use my xfi aswell.

Spazzfish · 28 Aug 2010 at 21:58

http://www.hardocp.com/article/2010/08/16/sli_cfx_pcie_bandwidth_perf_x16x16_vs_x16x8/

Mr Krugga · 28 Aug 2010 at 22:48

It's 3% at most really with the same card(s).

Antx777 · 29 Aug 2010 at 00:31

Thanks for that link spazzfish.
Yes Johnny, the "air-flow" helps with the room so its a plus there i guess.

Ant

Antx777 · 29 Aug 2010 at 05:39

By the way, my Top card in the SLI config, is 74c in IDLE mode, whilst the bottum card is 51c with fan speed at 48%. However, when I crank the fan up to max, the top card remains 74c but the bottum card dips to 40 - or less even. the top card doesn't chage at all. when i swapped the card over, the "top card " was untouchable, whilst the other was lukewarm. Is this normal for thse cards/setup

TIA

EDIT User ERROR

I forgot to Syncronise fans in MSI afterburner, its ok Now

Ant

johny dolan · 29 Aug 2010 at 08:23

Antx777 said:
Thanks for that link spazzfish.
Yes Johnny, the "air-flow" helps with the room so its a plus there i guess.

Ant

The slots are very close on my mobo so when i sli or xfire the cards are very close together and temps suffer.

http://7527920078133950558-a-180274...mhkWjYj_FBu3nOMfUHEDiUBBIoJNkS&attredirects=0

Pic using both x16 slots.

Freakbro · 29 Aug 2010 at 15:40

I was wondering about this, especially since my top card atm is running 9*c hotter than the bottom card, which at idle isnt a problem, but when under full load (Kombustor) the top card is getting pretty warm now at stock clock speeds (85* @ 80% fan)

Thing is, I have the sli for nvidia surround, (3 x 24" monitors @ 5760 x 1080) - will the 3% drop off in the bottom card make a difference for that or would i make up more than that by having the temperature headroom to overclock them more.

Any thoughts?

johny dolan · 29 Aug 2010 at 16:19

The tests ive done show zero loss of performance using the x8 slot Freakbro.

CaptainRAVE · 29 Aug 2010 at 16:25

Freakbro said:
I was wondering about this, especially since my top card atm is running 9*c hotter than the bottom card, which at idle isnt a problem, but when under full load (Kombustor) the top card is getting pretty warm now at stock clock speeds (85* @ 80% fan)

Standard for a multi-gpu setup. Actually, seems lower than most.

Freakbro · 29 Aug 2010 at 16:39

johny dolan said:
The tests ive done show zero loss of performance using the x8 slot Freakbro.

So i would be better to move the bottom card down to the 3rd pci-e slot (giving the top card some breathing room) and then overclock both cards

CaptainRAVE · 29 Aug 2010 at 16:43

Freakbro said:
So i would be better to move the bottom card down to the 3rd pci-e slot (giving the top card some breathing room) and then overclock both cards

Will certainly give them some breathing room.

Freakbro · 29 Aug 2010 at 17:13

:
Originally Posted by Freakbro
I was wondering about this, especially since my top card atm is running 9*c hotter than the bottom card, which at idle isnt a problem, but when under full load (Kombustor) the top card is getting pretty warm now at stock clock speeds (85* @ 80% fan)

Click to expand...

Standard for a multi-gpu setup. Actually, seems lower than most.

I did install a scythe gentle typhoon into the case, on one of the HDD bays, at the end of the gfx cards so it blows into them

johny dolan · 29 Aug 2010 at 18:29

I have also fitted a small fan infront of my cards to give extra cooling as my 5970 was hitting 90c under load when both cards were in slots x16 now with the 5870 in the x8 the highest the 5970 hits is 70c

Freakbro · 30 Aug 2010 at 12:59

Ive just come across two snags with moving the 2nd 470 into the 3rd pci-e slot..

1) The antec 1200 only has 7 expansion slots in the back , so the exhaust ports of the bottom card dont have anywhere to vent , well only into the case..

2) the card wont clip into the pci-e slot as it is pressing against the front panel connectors (pwr switch, reset, hdd led) - maybe the front panel usb header and audio connectors might cause a problem too, but the switch ones stand up higher.

So I guess unless i cut holes and mod cables i wont be moving the card, shame