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580gtx + 295gtx (for physics) = how any psu watts?

jmartin357

Member
Oct 6, 2004
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0
66
I'm looking to upgrade to a 580 from a 295 and then dedicate the 295 to physics... but I have a 750 watt psu (I think antec) psu and an intel 965. Will I need more psu to make that happen?

Thanks!
 

toyota

Lifer
Apr 15, 2001
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sell the gtx295 and get something like a gts450 if you think you really need a physx card. it would be silly to use a huge dual gpu card for the 2 or 3 games you may ever even play that use hardware physx. plus only one gpu of the gtx295 would even be used. personally I would just run graphics and physx on the gtx580.
 

tigersty1e

Golden Member
Dec 13, 2004
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the gts 450 would probably pull down your 580.

some people have done physx tests with high end cards. I can't remember the actual results, but the gist is that you want a capable card for physx like a 460 at a minimum.
 

toyota

Lifer
Apr 15, 2001
12,957
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the gts 450 would probably pull down your 580.

some people have done physx tests with high end cards. I can't remember the actual results, but the gist is that you want a capable card for physx like a 460 at a minimum.
no it would not. if anything the gts450 would be almost the perfect compliment to the gtx580. a gtx460 would be overkill for the most part.

btw his gtx295 would be like having something a little bit faster than a gtx260 since only one gpu would be used anyway.
 
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happy medium

Lifer
Jun 8, 2003
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Sell the gtx295 and grab a gtx555ti for 105$, that would be perfect.

You can have some money left over for a 1tb harddrive or something.
 

happy medium

Lifer
Jun 8, 2003
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yep or just oc a gts450 to 900mhz if he can find one of those for 20-30 bucks cheaper.
oh crap your right they have the same amount of sp's.

Well I would suggest something about the same sp power as a 260gtx (216).
ARe the older sp's weaker than ones on the new cards?

What I'm saying is are a 260gtx 192 sp's as strong as the gts450 192 sp's?

Mabe a cheap gtx460 SE (119$) would be better? 244 sp's
It would make a better backup card also.
 

toyota

Lifer
Apr 15, 2001
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oh crap your right they have the same amount of sp's.

Well I would suggest something about the same sp power as a 260gtx (216).
ARe the older sp's weaker than ones on the new cards?

What I'm saying is are a 260gtx 192 sp's as strong as the gts450 192 sp's?

Mabe a cheap gtx460 SE (119$) would be better? 244 sp's
It would make a better backup card also.
since all physx seems to care about is the sp power, the gts450/gtx550 ti with 192sp at 1800 should easily be faster than the gtx260 216sp at 1250 or so.

basically a gts450/gtx550 ti with 192sp at 1800 should easily match a gtx275/280 for handling physx.

and as you can see here there's not much point in anything faster than that with a gtx480. of course his gtx580 is a little faster but it wont make too much difference in making a physx card choice.


gif upload
 
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happy medium

Lifer
Jun 8, 2003
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since all physx seems to care about is the sp power, the gts450/gtx550 ti with 192sp at 1800 should easily be faster than the gtx260 216sp at 1250 or so.
gts450 it is, :)

SInce we have come up with a good solution,let me ask you this.
WHy is a 260gtx 192 faster than a gts450 or isn't it?
It can't be just the memory bandwidth right?
 

toyota

Lifer
Apr 15, 2001
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gts450 it is, :)

SInce we have come up with a good solution,let me ask you this.
WHy is a 260gtx 192 faster than a gts450 or isn't it?
It can't be just the memory bandwidth right?
in some games the gts450 has now caught up to even the 216sp gtx260 because of newer drivers. overall though a 192sp gtx260 and 192sp gts450 would be pretty close now. the gtx260 does have much more bandwidth and also has more tmus. clock for clock the gtx260 would probably win nearly every time but the gts450 can and does run at much higher clocks.
 
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happy medium

Lifer
Jun 8, 2003
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in some games the gts450 has now caught up to even the 216sp gtx260 because of newer drivers. overall though a 192sp gtx260 and 192sp gts450 would be pretty close now. the gtx260 does have much more bandwidth and also has more tmus. clock for clock the gtx260 would probably win nearly every time but the gts450 can and does run at much higher clocks.
Ah the tmu's I forgot about them,:thumbsup:
thanks bud.
 

jmartin357

Member
Oct 6, 2004
47
0
66
so, if I didn't want to mess too much with selling and buying a new card, do you folks think my psu is up to the task?
 

happy medium

Lifer
Jun 8, 2003
14,387
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so, if I didn't want to mess too much with selling and buying a new card, do you folks think my psu is up to the task?
Yes, it will be ok, only because it will only use 1 gpu of the gtx295.

Just don't go crazy with any sort of overclocking.
 

toyota

Lifer
Apr 15, 2001
12,957
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so, if I didn't want to mess too much with selling and buying a new card, do you folks think my psu is up to the task?
so you would rather fool with wastefully sticking a gtx295 in there for 2 or 3 games that use hardware physx? just sell the gtx295 and get something more appropriate. you wont have to worry about power then plus you will have some extra money. btw can you please tell me what games you are wanting to play that have hardware physx?
 

jmartin357

Member
Oct 6, 2004
47
0
66
so you would rather fool with wastefully sticking a gtx295 in there for 2 or 3 games that use hardware physx? just sell the gtx295 and get something more appropriate. you wont have to worry about power then plus you will have some extra money. btw can you please tell me what games you are wanting to play that have hardware physx?
the batman games. I d/led the trial for asylum and it looked pretty fun, but at max settings was crazy slow. I was hoping to correct that...
 

toyota

Lifer
Apr 15, 2001
12,957
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the batman games. I d/led the trial for asylum and it looked pretty fun, but at max settings was crazy slow. I was hoping to correct that...
there is no way it should have been slow. I could average 40 fps at 1920x1080 with very high settings and physx on high with just a gtx260. for a game like Batman that using hardware physx you need to use one gpu for physx and the other for graphics instead of using sli.
 

jmartin357

Member
Oct 6, 2004
47
0
66
ok, just to clarify - I have the 295 now. I maxed the game to everything, including 25x16 and physics... it was absurdly slow. that demo aside, my desire to move to the 580 is dx11 related (and yes, I realize that's roughly as awesome as my px plan :))

in any case, my plan was to spend $500 on a top end card and 20 mins of install time. I was hoping to avoid ebay, fedex any any related frustration. I'm not espeically averse to upgrading the psu, but that cascades into a new ups and possibly even some electrical work. hm, I'm spending too much money on the old pc... :)
 

happy medium

Lifer
Jun 8, 2003
14,387
475
126
ok, just to clarify - I have the 295 now. I maxed the game to everything, including 25x16 and physics... it was absurdly slow. that demo aside, my desire to move to the 580 is dx11 related (and yes, I realize that's roughly as awesome as my px plan :))

in any case, my plan was to spend $500 on a top end card and 20 mins of install time. I was hoping to avoid ebay, fedex any any related frustration. I'm not espeically averse to upgrading the psu, but that cascades into a new ups and possibly even some electrical work. hm, I'm spending too much money on the old pc... :)
I assumed your pc had a higher end cpu, what cpu are you using?
I noticed you have a Intel 965 chipset, which worries me about your cpu speed.

Your gtx295 could be running out of memory at that resolution.
Are you using tons of AA?
Mabe try dropping a setting or 2?
 
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