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Two 275GTX in SLI + 8800GTX for dedicated Phsyx?

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ShaggyTDawg

Registered
Joined
Jan 24, 2008
Hello all,
I've dug around a little and wasn't able to find a thread that seemed to match enough to what I'm asking so here goes:

I'm likely going to get two Nvidia 275GTX (1792MB version, EGVA:bday:) for X-mas. I have an old 8800GTX (G92 version, 512MB, EVGA) that has served me well. I'm running EVGA's 780i board which has 3 PCI-E 2.0 x16 slots so it can in theory run 3 way SLI.

I however would like to run my two new 275GTX's in SLI and use my old 8800GTX as a dedicated Physx processor. Is this reasonable and do able? All three cards don't have to be SLI bridged correct? Just my 275GTX's right?

Also what would you recommend for PSU?

I'm running a Q6600(stock), 2 x 2GB DDR800(I think 800), 2 x 7200rpm 320GB, 1 x 10000rpm raptor, one DVD burner, swiftech (I think) water pump, and soon the cards listed above.

I'm looking at a 1200Watt PSU, any reason to think that won't be enough?

Cheers!
 

jokers_greg

Member
Joined
Jan 31, 2005
Location
Mississauga, Ontario
1200W will be more than enough, as for the actual concpet of doing this, I'm pretty sure PhysX was only on 9xxx series cards, but if it also applies to 8xxx series cards, your GTX is way overkill. I'd sell it and pick up a 9600 or something, use the extra cash from that transaction for something else.
 
OP
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ShaggyTDawg

Registered
Joined
Jan 24, 2008
1200W will be more than enough, as for the actual concpet of doing this, I'm pretty sure PhysX was only on 9xxx series cards, but if it also applies to 8xxx series cards, your GTX is way overkill. I'd sell it and pick up a 9600 or something, use the extra cash from that transaction for something else.

PhsyX support was picked up w/ the 8xxx series. See here. FTA:

In August 2008, Nvidia released drivers that allow GeForce 8 series and above video cards to implement PhysX processing.http://en.wikipedia.org/wiki/PhysX#cite_note-8

I've also run games on that card that have PhsyX support (Batman: Arkham) and I get this annoying overlay that says PhsyX -> GPU.

I've already got this 8800GTX, and I'm not strapped for cash or anything, so I'm just gonna keep it to run PhysX.

I just ordered this:

2 x EVGA 017-P3-1175-AR GeForce GTX 275 1792MB 448-bit DDR3 PCI Express 2.0 x16 SLI Support Video Card - Retail

:comp:

BFG Tech EX-1200 BFGR1200WEXPSU 1200W Continuous Rated at 40°C ATX12V 2.2 / EPS12V 2.91 SLI Ready CrossFire Ready 80 PLUS Certified Modular Active PFC Power Supply - Retail :cool:

Let me know what you guys think.

Thanks!
 
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ShaggyTDawg

Registered
Joined
Jan 24, 2008
Apologies... I got confused on my GTX's and my GTS's....

I have an 8800GTS (512MB, G92) that I'm currently using as my primary video card that will become my dedicated PhysX processor... not an 8800GTX.:shrug:
 

jokers_greg

Member
Joined
Jan 31, 2005
Location
Mississauga, Ontario
ah there you go, a GTS is less of an overkill, but still lol. PhysX isn't THAT demanding. Yeah I wasn't sure if it started in 8xxx or 9xxx, but I recall using it on my 9800GX2, frame rates weren't really affected, but I didn't run anything crazy like crysis or anything like that.

1200W is still way too much power, but better to be safe than sorry.
 
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ShaggyTDawg

Registered
Joined
Jan 24, 2008
I forgot to mention in the list of stuff to power in my PC... I've got 6 120mm fans on my radiator and another 2-4 120mm fans in my case (too lazy to look and count).

All of the PSU calculators I've used have estimated at least 1000 watt PSU. So might as well be safe.
 

Amtrak

Member
Joined
Jul 23, 2008
What resolution are you playing at? I think almost regardless of everything, I'd ditch the 8800 altogether and just do PhysX processing with the 275's. Few games utilize PhysX, fewer still are worthwhile to play, and only one I know of (Mirror's Edge) looks good using it.
 

Charr

Member
Joined
Oct 28, 2006
Location
Raleigh, NC
I say you should dump the existing card, because you don't need that much power for Physics processing. Plus, the 8800GTS will add some serious breathing problems for the other two new cards.
 

amnios

Member
Joined
Dec 31, 2009
http://www.tomshardware.com/reviews/batman-arkham-asylum,2465-8.html

That will show you some benchmarks for Arkham Asylum using physx with different configurations... What I got from reading it is that running a GTX260 as your main and a 9600GT as dedicated gave you only about 3 - 6 frames per second slower performance than running a 260 with a second 260 dedicated to physx! (running everything on max and 1920 x 1200 and physx set to max, not normal)

So by that numbers I'd say using anything higher than a 9600GT is overkill because 3 - 6 frames is nothing imo.

I use a 512MB 9600 GT dedicated with a GTX280 and I'm very happy. And I do believe that physx is great for games. Imagine what modern Warfare 2 would be with physx additions!!!