What makes multiple GPUs in a system different from multiple CPUs? Why is it that multiple core CPUs are now standard, but single GPUs are still preferred over multiple GPUs(SLI, crossFire)?
>>55157746
The increase in performance is moderate at best and the returns diminish quickly with the addition of more units
In a multi core cpu, the cores are designed to work together so the performance boost is much more noticeable.
a GPU is just a processor with a effectively thousands of CPUs on the die that perform low intensive calculations.
>>55157746
Wouldn't the middle GPUs pretty much burn up in this setup…
>>55157746
Not only does that setup look like a heating nightmare, but what on earth do you need 4 titans to run?
>>55157874
rendering ur mum
>>55157838
They're blower coolers that push the air through the interior of the card and out the back rather than away from it and into the case, they're ideal for SLI.
>>55157746
Videocards need assload of non-straightforward driver work to get anything done, so not just multi-GPU, but basically any special feature needs lots of crap to get benefit from.
Similar problem that hampers GPGPU.
>>55157838
They do. Watercooling is really useful for multi-GPU setups.
>>55157895
savage
>>55157746
You're confusing multiple cores with multiple units. Two GPUs is analogous to using two CPUs (if you didn't know already, yes it exists).
Bot CPUs and GPUs have multiple cores, in fact even the lowest end GPUs have more cores than the highest end CPUs.
>>55157746
I though GPUs have a shitload of cores doing small calculations each?
overhead
keeping everything in sync etc. takes a lot of work so you don't really get 2x the performance and there are other. it's much easier for multiple cpu cores on the same chip. a lot of things are shared by several or all cores. with 2 seperate cpus you have to keep everything in sync etc. which is not that easy and a lot of work (and money) goes into making multiple cpus work together smoothly.
>>55157746
Multicore CPUs are generally utilized by software. There is also an increase in adding CPUs to a system.
GPUs are by nature massively parallel and therefore can be designed to become more powerful in a single core situation. The difficulty with multi-GPU setups are that software don't take advantage of extra GPUs are effectively and that it's more cost effective to add more parallelism to a single GPU core than to add multiple cards.
There are exceptions, such as with ARM Mali and Imageon VR chips as well as some high end GPUs. The GPUs are, unfortunately, not double the performance.
The other exception is software. DX12 handles multiple cards much better and there is a noticeable increase in performance in multi-card setups.
In theory, you could get a more than 100% increase in performance if you create a driver that is specifically designed for your exact system but that's not likely to happen.
>>55157746
Using many GPUs in a system is very sensible - if you're doing high performance computing, that is.
For gaming, the focus is less on "getting more frames calculated" but more on "getting frames delivered in time". SLI and Crossfire aren't particularly good at that, because splitting the workload that quickly usually results in the distribution not being even (communication between the cards - another performance drain aside). So if you say: one card renders the left of the screen, the other the right, sometimes one card doesn't have much to do because it's rendering a wall or something simple like that, and the other has the hard work. So the resulting performance is sometimes only that of the harder working one, because the other one isn't contributing much.
Then there's frame times that might suffer from SLI/XF. But on AMDs side that doesn't matter, because frame times are uneven as fuck anyways (shots fired)
>>55157746
multi-gpu setups are good for productivity, rather overkill for muh gaymes.
>>55159944
this anon is right
