Question When Using 2 GPUs in a PC Build does the VRAM get shared between GPUs?

[Gamefreaknet]

(Basically the title):
So lets take the 4060ti for example it has 8GB VRAM. If you used 2 4060ti's youd have a total of 16GB VRAM however can both GPUs share their VRAM (so if a game demands 12GB VRAM for all the textures and shaders could the second GPU offload share some of its VRAM since both GPUs are actively running) despite being on different PCIE 16 slots?

 

[SkyNetRising]

No. Doesn't work like that.

 

[Deleted member 2731765]

No, they cannot share. Also, you can't use 2 4060 Tis in SLI mode either. Each card uses it's own frame buffer. Even in SLI mode, VRAM never gets stacked or added up.

You would be better off buying a SINGLE powerful GPU than going a different route.

 

[Nighthawk117]

Historically with Nvidia SLI no, each card had the same copy of data in it's VRAM. NVLink I think is different but I'm not aware of a game that supports it.

Even if it did, multiple GPU's is not an efficient way to run a game, it's much better to have a single more powerful GPU.

 

[Gamefreaknet]

No, they cannot share. Also, you can't use 2 4060 Tis in SLI mode either. Each card uses it's own frame buffer. Even in SLI mode, VRAM never gets stacked or added up.

You would be better off buying a SINGLE powerful GPU than going a different route.

can any of the 30series or 40series cards run in SLI (or the ARC A770)

 

[Deleted member 2731765]

can any of the 30series or 40series cards run in SLI (or the ARC A770)

Nvidia has dropped SLI or NVLINK mode on consumer gaming GPUs. There is no SLI support these days. Because it's not worth the hassle, and games don't scale well in dual-GPU configuration.

Even game developers have dropped coding for multi-GPU setups.

 

[Nighthawk117]

can any of the 30series or 40series cards run in SLI (or the ARC A770)

SLI was discontinued years ago and replaced by NVLink. The 3090 supports NVLink, I don't think any 40 series card supports it, in part because so few people use it.

 

[Gamefreaknet]

Nvidia has dropped SLI or NVLINK mode on consumer gaming GPUs. There is no SLI support these days. Because it's not worth the hassle, and games don't scale well in dual-GPU configuration.

Even game developers have dropped coding for multi-GPU setups.

Can 2 GPUs (same or different) still run on the same mobo without SLI?

 

[Deleted member 2731765]

Can 2 GPUs (same or different) still run on the same mobo without SLI?

Yes, You can, but only if your motherboard has enough PCIe slots, sufficient PCIe lanes, and a PSU that's strong enough to power both GPUs simultaneously.

But it's useful only for a specific reason, if you have more than one monitor. You can use one graphics card to run one monitor, and the second one to run the other monitor.

Why do you want to use two GPUs on your system ? For more external monitor support ? A single GPU can also support more than 1 monitor. Depends on how many ports are there.

 

[Eximo]

SLI and Crossfire apply to gaming only.

SLI and Crossfire are basically done. Even if the cards supported it, motherboards starting dropping support a few generations back. On AMD it was always a very premium feature and not all high end boards had it.

Intel does not support any form of multi-GPU.

DX12 does allow multiple, even different, discrete GPUs to be used simultaneously. However, this requires implementation from software developers. Only one retail game ever supported it. It never really worked right in that mode either. Having different GPUs caused more issues than it was worth. (Frame times were very inconsistent) Similar issue AMD had with Hybrid Crossfire, mixing APUs and Discrete GPUs proved problematic as well.

Multi GPU was replaced with single massive GPUs, which is why power requirements and GPU sizes have gotten as outrageous as they have.

Fastest SLI possible is dual 3090Ti at a horrendous power cost, you also need an SLI capable motherboard, which with current generation hardware is about a $500+ motherboard with only the very top few boards offering support for enthusiast overclockers. None of the 3080 series and below support SLI. In the twenty series the 2070 Super and up (specifically excluding the 2070) were capable of SLI. You have to go way back before mid-range cards supported it, and any mid-range card of today would perform better on its own.

You can have any number of GPUs in a system and task them with any software capable of doing so. Video encoding, AI, Large Language Models, Mathematics/Science, Simulation, etc which all require massive parallel processing or floating point math are good applications.

And as mentioned, additional GPUs allow or additional displays, but for the typical multi-monitor setup a single GPU is sufficient.

 

[Gamefreaknet]

Yes, You can, but only if your motherboard has enough PCIe slots, sufficient PCIe lanes, and a PSU that's strong enough to power both GPUs simultaneously.

But it's useful only for a specific reason, if you have more than one monitor. You can use one graphics card to run one monitor, and the second one to run the other monitor.

Why do you want to use two GPUs on your system ? For more external monitor support ?

Basically yes for a multi monitor setup? Thinking of 3 Monitors: 2 on the side and 1 central

 

[Eximo]

If you mean multi-monitor gaming, those would all need to use the same GPU.

If you mean to have secondary screens, they will run just fine off the same GPU you play the game with.

 

[hotaru.hino]

If you want to know why VRAM doesn't combine in multi-GPU setups is simply because there's no interface fast enough to allow for data sharing that they could use in a practical manner i.e., without bulky or expensive connections. This is also on top of the fact that now there's another layer of memory that the GPU has to check (if it's not in its VRAM, it has to go to the other card's VRAM), which could induce more latency which is something you don't want in real-time 3D rendering.

And since the "most compatible" multi-GPU rendering mode is alternate-frame rendering, they both need the same assets anyway.

 

[Nighthawk117]

Can 2 GPUs (same or different) still run on the same mobo without SLI?

Yes they can, however the benefit of doing this would be for non gaming workloads. I've done this once before and found the GPU's sit so closely together that they get very hot. Ideally you would want a large case and a board that allowed you to space the GPU's out a little. Also if your running multiple GPU's you would want a high core count CPU in order to support them.

 

[Gamefreaknet]

For reference Build here: Link
Ebay CPU Link

Component		Selection	Price
CPU			Intel Core i9-7900X 3.3 GHz 10-Core Processor	£113.15
CPU Cooler			Thermaltake TH360 ARGB Sync 59.28 CFM Liquid CPU Cooler	£89.99	Buy
Motherboard			Asus ROG Strix X299-E Gaming II ATX LGA2066 Motherboard	£219.00	Buy
Memory			Corsair Vengeance RGB RS 32 GB (2 x 16 GB) DDR4-3200 CL16 Memory	£68.08	Buy
Storage			ADATA Legend 800 2 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive	£62.99	Buy
Video Card			MSI GAMING X SLIM GeForce RTX 4060 Ti 16 GB Video Card	£513.48	Buy
Case			CiT Blade ARGB ATX Mid Tower Case	£57.99	Buy
Power Supply			Antec NeoECO Gold 850 W 80+ Gold Certified Fully Modular ATX Power Supply	£94.60	Buy
Total:	£1219.28

(I have only listed one GPU currently as I am not sure if a second GPU would work in the build although there are sufficient mobo PCIE x16 slots I do acknowledge that for another GPU I would need something closer to a 1200w PSU)

 

[Nighthawk117]

Basically yes for a multi monitor setup? Thinking of 3 Monitors: 2 on the side and 1 central

You may find you don't need to do this at all and you can support all 3 monitors through one GPU. You would need to check the ports first just in case any are shared. If you have an Intel CPU (non F) or AMD 7000 CPU you could also plug in an extra monitor into the iGPU if you ran out of connections on your GPU.

 

[Eximo]

For reference Build here: Link
Ebay CPU Link

I can conceive of no reason to build this system today.

Motherboard is about the same price you would pay for a higher end consumer board, and the CPU is quite old, though fairly cheap, it still wouldn't be as good for games as a mid-range 13th gen Or Zen 4 CPU.

Can't really recommend a 4060Ti over an RX6800 either.

 

[Eximo]

Try this:

PCPartPicker Part List

CPU: Intel Core i5-13400 2.5 GHz 10-Core Processor (£209.99 @ Amazon UK)
CPU Cooler: Thermalright Phantom Spirit 120 SE ARGB 66.17 CFM CPU Cooler (£56.40 @ Amazon UK)
Motherboard: ASRock B760 Pro RS/D4 ATX LGA1700 Motherboard (£124.99 @ Amazon UK)
Memory: Corsair Vengeance LPX 32 GB (2 x 16 GB) DDR4-3200 CL16 Memory (£58.98 @ Amazon UK)
Storage: Crucial P5 Plus 2 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive (£93.99 @ Amazon UK)
Video Card: ASRock Phantom Gaming D OC Radeon RX 6800 XT 16 GB Video Card (£507.98 @ Overclockers.co.uk)
Case: CiT Blade ARGB ATX Mid Tower Case (£57.99 @ Box Limited)
Power Supply: Corsair RM750e (2023) 750 W 80+ Gold Certified Fully Modular ATX Power Supply (£115.47 @ Scan.co.uk)
Total: £1225.79
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2023-08-01 17:34 BST+0100