PDA

View Full Version : SLI + Physx question



Zero.exe
11-09-2016, 02:34 AM
Hey all,

Quick PC Setup for reference:
-Asus Maximus VI Hero
-i7 4770k
-1000 Watt Gold PSU

So I have two Asus GTX 770 2gb non-reference Graphics cards. I Would like to run them in SLI on my M-VI Hero board. I was wondering, If I were to pick up a cheap GTX card to run as a physx card, would that help increase fps? Is it possible to run another card on the same mobo that already has two cards in sli?

Thanks for your input.

ASUS-OP
11-28-2016, 05:04 AM
Hi there,

It will only help when the GTX card dedicate for PHYSX can handle the PHYSX calculations thrown at it.
Interesting finds here: http://www.technologyx.com/featured/using-a-graphics-card-as-a-physx-processor-beneficial-or-not/

Yes, you can have two cards in SLI plus another card solely for PHYSX.


Hey all,

Quick PC Setup for reference:
-Asus Maximus VI Hero
-i7 4770k
-1000 Watt Gold PSU

So I have two Asus GTX 770 2gb non-reference Graphics cards. I Would like to run them in SLI on my M-VI Hero board. I was wondering, If I were to pick up a cheap GTX card to run as a physx card, would that help increase fps? Is it possible to run another card on the same mobo that already has two cards in sli?

Thanks for your input.

Korth
12-02-2016, 08:21 PM
Here's another excellent PhysX article. (http://www.volnapc.com/all-posts/how-much-difference-does-a-dedicated-physx-card-make)

A dedicated PhysX card will rarely increase peak/average FPS - it will usually "smooth" out FPS rate stuttering and reduce the impact of FPS "dips" during sustained heavy GPU loading - and only when sheer quantity of complex object/motion/collision calculations outweighs rendering calculations. Few games benefit from PhysX, and very few of these optimize coding for PhysX well enough to make a substantial difference.

You'll get best PhysX results with a third 2GB GTX770, on a few games. Mismatched SLI/PhysX cards will actually diminish your overall FPS, on most games.

To be honest, I think a single used 4GB GTX980 or a pair of used 2GB GTX960 cards would a better investment than a third 2GB GTX770 - unless you can pick one up cheap and/or you happen to be playing game titles which will benefit greatly from PhysX.

Don't forget that your PSU needs to be able to handle all cards. Reference GTX770 card specs (http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-770/specifications) are 230W each, nonreference ASUS GTX770-DC2OC-2GD5 card spec (https://www.asus.com/ca-en/Graphics-Cards/GTX770DC2OC2GD5/specifications/) are "up to 300W" each. GTX770 cards have one (75W) 6-pin and one (150W) 8-pin power input which (along with 75W from the PCIE slot) can provide a maximum of 300W. That's 900W of PSU (with some compatible combination of six 6-, 8-, or 6+2-pin PCIE power outputs) for the three graphics cards alone, and the MAXIMUS VI HERO User Manual (http://dlcdnet.asus.com/pub/ASUS/mb/LGA1150/MAXIMUS-VI-HERO/E8459_Maximus_VI_Hero.pdf) suggests 350W+ minimum for the system, so I think a total of 1250W+ PSU is required - especially if you're running your system heavy or overclocking anything.

And your PhysX card would need to be plugged into your Maximus VI HERO's black PCIE slot. A double-width GPU card would overhang the bottom edge of the mobo, there might not be enough space (or slot holes) to fit it into every ATX PC chassis - you could use PCIE slot risers/extenders if truly desperate, although they'd add signal latencies which would work against performance gained from this card, so a bigger (full-EATX) case would be a better solution.