Dual GPU without SLI&CrossFire

[Shadevil]

Hi,

my gaming (oldish) rig still runs on AMD R9 380 2GB. While the Crossfire would be nice, there seems to be no chance to get hands on second R9 380 (I am looking for a one for couple months and no luck). So that possibility is likely off the table. With the current GPU prices I won't be upgrading any time soon. So it seemed I am stuck with what I got.

But I found out, you can have a second non-SLI card in your computer and still benefit. I have in my even older and not anymore used setup a nVidia GT 640 1GB and somewhere also lies a parody on GPU, but much less power hungry, nVidia n210 (please do not ask). Therefore as I have a spare PCI-E slot in my current rig - I started to wonder how to utilise that. There indeed might occur problems with physical limitations (dimensions & airflow) as my R9 is double deck and case of mine is not exactly vast) - but let's do forget about that for a moment.

What benefit aside extra video output for a third and fourth monitor (which I do not have) would I get out of it? I am aware of the fact that for gaming the second card would not parcitipate directly (as non SLI/Crossfire) - however would I get some PhysX out of the second card (especialy relevant for me as my main GPU is AMD)? Could it otherwise help my CPU (as I am currently stuck with FX 4300 until I decide to switch MBD/CPU)? Or would it just sit there draining power supply? (for sake of the case, lets asume no monitor would be plugged into the 2nd card).

And if I could benefit from such second card - how to achieve it? What drivers should I install? Wouldn't it collide with my main card drivers? How to tell SW (game) to use the capabilites of the second card, e.g. for PhysX or whatever it could be doing? Is that worth the extra energy consumption? is n210 enough for that (for its low energy consumption rate and not being main gpu) or is GT 640 the only way?

Consider there is no investment required from my side as I do already own the second card(s)...

I am only aware of using 2nd gpu for Fold@Home projects, but that is not desirable for me (I have dedicated 2 special setups just for that) and I have no interest in virtual mining. I do run Windows 10...

Thank you all for your feedback...

 

[InvalidError]

1GB of VRAM is not enough to be of any use in recent games, trying to use the GT640 in what very few titles support explicit multi-graphics adapters would most likely hinder performance instead of help it.

 

[RobCrezz]

Theres no benefit for gaming. Just that you could connect more screens. Or if you are doing other kinds of workloads like rendering you could use multiple different cards.

 

[4745454b]

But I found out, you can have a second non-SLI card in your computer and still benefit.

Who told you that? I have three monitors on my desk and my TV hooked up to my single 7950/R9 280. You said you don't even have monitor 3 and 4 so this is moot, but even if you did have them you could still use your 380. And while it is possible to use the GT640 as a PhysX card, you shouldn't. First, there are VERY few games that support GPU accelerated PhysX. There might be more since I last looked, but there were around 25 in total. You probably only care about 5 of them or so. Second, because your main card is an AMD card you'll need to use hacked drivers to get this setup working. Nvidia decided that unless you have an Nvidia main card they won't allow you to use an old Nvidia card to do this. The hacked drivers are usually several generations old so anything super current won't work. In general this is possible to do but is just a headache inducing thing to do.

I am currently stuck with FX 4300

Ah, the reason for the question. You have an old and slow CPU and you want to put something in the PC to make it faster. CPUs and GPUs don't really work together like this. You really need a faster CPU, not an old GPU in the PC basically just drawing power.

 

[ZRace]

You could definitely use the GT 640 in games that make use of the Nvidia PhysX. But to get it working with the R9 380, you'll have to disable driver updates through windows (if on win 8.1/10) as well as use modified Nvidia drivers.
If you can cope with those setup complications and have enough games that support it, it may make sense.

As for using it as a boost in DX12 titles... that might not go so well. The GT 640 is so much slower it might actually make things worse, but that has already been said.

 

[Shadevil]

But I found out, you can have a second non-SLI card in your computer and still benefit.

Who told you that? I have three monitors on my desk and my TV hooked up to my single 7950/R9 280. You said you don't even have monitor 3 and 4 so this is moot, but even if you did have them you could still use your 380. And while it is possible to use the GT640 as a PhysX card, you shouldn't. First, there are VERY few games that support GPU accelerated PhysX. There might be more since I last looked, but there were around 25 in total. You probably only care about 5 of them or so. Second, because your main card is an AMD card you'll need to use hacked drivers to get this setup working. Nvidia decided that unless you have an Nvidia main card they won't allow you to use an old Nvidia card to do this. The hacked drivers are usually several generations old so anything super current won't work. In general this is possible to do but is just a headache inducing thing to do.

I am currently stuck with FX 4300

Ah, the reason for the question. You have an old and slow CPU and you want to put something in the PC to make it faster. CPUs and GPUs don't really work together like this. You really need a faster CPU, not an old GPU in the PC basically just drawing power.

Thank you for the great answer - I suspected that any potential benefit would be minor and at too much "cost" (time&effort). Your question summarise it very nicely. I am not going to mess with drivers.

However my CPU is not the reason for proposed idea.I purchased it two weeks before official anouncement of Ryzen being on AM4 got to me - with hope that I would upgrade to new generation soon. Well, it was bad idea. But as changing CPU would now mean new MBD, which would likely force me to get new RAM modules (currently DDR3) and finaly to get SSD. All that would render my GPU outclassed by rest of PC, so in conclusion I would be keeping case and hopefuly powerunit. So in the meantime I was looking to any minor (free of cost) solution to even slightly boost it up.

So... I will completely rebuild my PC, when it eventualy loses its breath.

EDIT: Point is would I have a decent rest of PC I would buy new GPU (once they are stocked again) without hesitation, my current situation is to squeeze any last potential from my rig at no cost and then be done with it, while I save money for complete rebuilding.

But my PC handles new games suprisingly well (quite demanding Kingdom Come: Deliverance can run 95% of game on medium-to-high settings). Indeed it is thanks to me having only FHD monitor at only 60Hz... I was surprised even recording at the same settings was possible (albeit at 30fps).

FX 4300 has one secret in its pocket. While it lacks modern technologies (and it is very obvious in titles/SW utilising it) it still has a decent solution - raw power. It is clocked fast compared to modern CPUs single core "clock" and some titles need just that (or it seems so), or it can partialy compensate the lack of features.

I was lucky with the R9 380 aswell (I picked it back then only as my primary choise was not on stock) as while texture size can and is sometimes limit factor, it still can do its job damn well. I do believe that until we get new (true) generation of consoles, my current righ will handle stuff, even though it will be on minimal-to-medium settings. Once new consoles arrive, my righ will be completely obsolete and will be either completely rebuilt or exchanged.

 

[InvalidError]

FX 4300 has one secret in its pocket. While it lacks modern technologies (and it is very obvious in titles/SW utilising it) it still has a decent solution - raw power. It is clocked fast compared to modern CPUs single core "clock" and some titles need just that (or it seems so), or it can partialy compensate the lack of features.

Clock frequency is only half the battle: throughput = IPC * clock frequency. In most light to moderately threaded game benchmarks, even the FX-9590 (5GHz turbo) gets destroyed by the i3-3220 or similar due to the i3's far superior IPC.

If you look at FX vs Ryzen benchmarks, the FX get completely destroyed in practically every case despite Ryzen having similar or lower clock frequencies. Having substantially higher IPC (as much as 50% better than AMD's pre-Ryzen architectures) makes a huge difference.

 

[RobCrezz]

But I found out, you can have a second non-SLI card in your computer and still benefit.

Who told you that? I have three monitors on my desk and my TV hooked up to my single 7950/R9 280. You said you don't even have monitor 3 and 4 so this is moot, but even if you did have them you could still use your 380. And while it is possible to use the GT640 as a PhysX card, you shouldn't. First, there are VERY few games that support GPU accelerated PhysX. There might be more since I last looked, but there were around 25 in total. You probably only care about 5 of them or so. Second, because your main card is an AMD card you'll need to use hacked drivers to get this setup working. Nvidia decided that unless you have an Nvidia main card they won't allow you to use an old Nvidia card to do this. The hacked drivers are usually several generations old so anything super current won't work. In general this is possible to do but is just a headache inducing thing to do.

I am currently stuck with FX 4300

Ah, the reason for the question. You have an old and slow CPU and you want to put something in the PC to make it faster. CPUs and GPUs don't really work together like this. You really need a faster CPU, not an old GPU in the PC basically just drawing power.

FX 4300 has one secret in its pocket. While it lacks modern technologies (and it is very obvious in titles/SW utilising it) it still has a decent solution - raw power. It is clocked fast compared to modern CPUs single core "clock" and some titles need just that (or it seems so), or it can partialy compensate the lack of features.

It really doesnt have raw power... Its IPC is terrible.