SLI / CrossFire FAQs

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Thomas Maher

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Ok will think about starting a thread on that. I have tried researching the rx 460 was it? The new amd card but all the prices were way above $200. Amazon does have the gtx 950 for like $169 but I don't think that will work. When will this 1060 be released and pricing on it? I seen the 1080 and 1070 near like $800-$900 or way above $500
 

Thomas Maher

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I live in the USA but it seems I cannot find right prices on ebay or amazon. I saw newegg have it for $199.99 but I never bought from newegg before.
 

Thomas Maher

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Can you help me find a good one maybe the 8gb one for $200 or can I mod the 4gb one to make it 8gb?
 
No one can guarantee that the 4 gigabyte one can be unlocked. At current some users are reporting it working, but it could change at any time. Since they all run under the same number, even if they change them, the end user will not know.

As for prices, many users like pcpartpicker(shows you all the places that sell a given product).
 

Thomas Maher

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Ok thank you. I won't really need the card till later this month or next month anyways
 

SuperTimmay

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Tdmitry

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Hmm...I think FAQ should be updated.


I didnt saw any info about modern status of 3- and 4-Way SLI.

BTW, that's the matter I'm here - how 3 and 4 way sli doing? Does Huan really disabled 3/4 Way at all, or there is a possibility to boot and even gain some boost from 3 cards yet?
 

8350rocks

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You *could* do a 3 or 4 way SLI/CF, but really anything beyond 2 cards is just overkill these days, IMO.

On another front, Vulkan has added multi-GPU support now...so that is a plus.
 



It's definitely not overkill @4K+; you need every ounce of horsepower to drive something like 1440p surround for example.
 
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Guest

Guest
I recently upgraded my motherboard & cpu to
Gigabyte AX370 Gaming 5
& Ryzen 5 1500x

I currently own two gpus
GTX 260²
&
GT 730

Would I be better upgrading to a 1060(or a 1070) or getting a pair of lesser cards & running them in SLI ?
 

8350rocks

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If you are playing @ 1080p/1440p - 1 big card is good.

If you are playing multi-monitor or 4K, then you probably want something like a 1080Ti/RX Vega, or a pair of 580/1070 in CF/SLI
 
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Guest

Guest

I use two monitors BUT I'll be gaming on one only. I watch cctv on the second monitor.
My monitors are pretty basic I have an AOC E2752VQ 27 inch Widescreen LED Multimedia Monitor as my gaming one & and an old AOC E2450w for the cctv
Does it still count as multi monitor if I'm only really gaming on one?
 


Does the video card need to decode the CCTV stream? If that is the case, then I don't think anything less than a 1060 6GB/RX480/RX580 would do. Otherwise, most of the burden will be on the CPU, so you might need a beefier CPU than video card to have good framerates.

Also, nVidia is kind of a hit and miss with multi-monitor setups. I'm usually inclined to suggest AMD to any person looking to use more than 1 screen, specially when they're different models and specs.

Cheers!
 
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Guest

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I don't believe it does I use software called ispy & foscam ip cameras https://www.amazon.com/Foscam-FI8910W-Network-Camera-Two-Way/dp/B006ZP8UOW?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B006ZP8UOW
 

Bem-xxx

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When CrossFire works, it could beat a 1080Ti.
[video="https://www.youtube.com/watch?v=dWsNoVpBZVA"][/video]
 

goldstone77

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AMD Bids Farewell To CrossFire After 12 Years, Retiring Brand In Favor Of mGPU
By Khalid Moammer
Sep 22

AMD-Radeon-R9-290X-CrossFire-Scaling1.jpg

AMD revealed today that it no longer refers to multi-GPU support by its long-standing Radeon brand known as CrossFire. This revelation came via PCWorld’s Brad Chacos, who was curious as to why Crossfire wasn’t mentioned in the company’s latest Radeon Software 17.9.2 drivers. He proceeded to email AMD to inquire about this apparent omission.

To his surprise AMD’s answer was that it’s transitioning away from the CrossFire brand, referring to it as a DirectX 11 era technology. “CrossFire isn’t mentioned because it technically refers to DX11 applications,” an AMD PR person told PCWorld. “In DirectX 12, we reference multi-GPU as applications must support mGPU, whereas AMD has to create the profiles for DX11. We’ve accordingly moved away from using the CrossFire tag for multi-GPU gaming.”
AMD further elaborated by saying that this is simply a branding decision not a technical one. The company is by no means ending multi-GPU support for its graphics cards, in fact its latest drivers enable multi-GPU support for its recently released Radeon RX Vega graphics cards with promises of 80%+ performance scaling.
AMD-Radeon-RX-Vega-multi-gpu-support.jpg

Multi GPU In The New DirectX 12 Era
Gone are the days of old when graphics card vendors had to hand-craft and optimize CrossFire & SLI profiles for multi-GPU to work at all in games. DirectX 12, unlike all of its predecessors, delegates this responsibility entirely to the game developer via a feature called Explicit Multi-Adapter. The API enables low-level access to the hardware, allowing developers to access each GPU directly and independently.
ExplicitLinked.png

ExplicitLinkedThere are two types of Explicit Multi-Adapter modes in DirectX12 “Linked” and “Unlinked”. Linked mode is only available when there are multiple identical GPUs in the system, similar to what CrossFire and SLI setups look like today. It allows for the computing/graphics resources and the memory pools of multiple GPUs to be combined into one larger addressable unit. This mode works by delegating similarly tasking workloads to each GPU, essentially cutting the overall work in half to complete it in a shorter amount of time.

One GPU could render one portion of the frame while the second could render another portion of the same frame for example. This is called Split Frame Rendering, SFR for short. This technique negates the limitations inherent in the traditional alternate frame rendering – AFR – technique used today in DX11 and older games, which involves mirroring the memory pools and introduces the need for frame pacing.
ExplicitUnlinked.png

Unliked mode is the second multi-GPU option under DX12. This mode is designed to take advantage of GPUs with different capabilities and even different vendors at once in the system. Yes, it allows developers to force NVIDIA and AMD GPUs to work together. The mode enables this through a thin abstraction layer allowing the different GPUs to swap data back and forth while giving developers total control. This mode enables developers to make use of discrete GPUs alongisde integrated GPUs or other discrete GPUs. With each GPU being treated as a completely independent graphics engine that the developers can choose to utilize for whatever they want.

This brings is to the concepts of CrossFire and SLI, which were introduced over a decade ago. As you can clearly tell the new new DirectX 12 multi-GPU capabilities have very little to do with SLI and CrossFire, which are essentially proprietary algorithms developed by each vendor to enable alternate frame rendering via the driver layer. Hence calling DirectX 12 multi-GPU support SLI or CrossFire is simply not accurate.

DX12 in and of itself does not rely on the proprietary SLI and CrossFire technologies that NVIDIA and AMD have developed. DX12 multi-GPU support stands on its own two feet. All that’s required of the vendor is to make sure that their hardware and software is compliant with the multi-GPU features built into DirectX 12. This is why AMD isn’t calling multi-GPU support in its latest driver release CrossFire, because it simply is not. Not anymore.
 
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3Dfx and NVIDIA's SLI technology are very different. The first is the connection method. 3dfx's Scal-Line Interleave requires a dedicated cable connection between the two graphics cards, as well as NVIDIA's Scalable. The link interface requires a connection daughter card that we call a "bridge." The second is the data transmission method. The SLI technology introduced by 3dfx is an analog transmission mode. The digital signal is converted to an analog signal and then the composite frame is manipulated. NVIDIA's SLI technology is digital signal transmission, calculated by two graphics cards. Synthesize images and convert them to analog signals. In addition to the above features, the core problem of multi-GPU technology is: image processing task assignment, 3dfx, NVIDIA's idea is Totally different. The first 3dfx uses the idea of ​​splitting the picture into blocks. The two graphics cards or GPUs render different parts of the screen's instant frame, respectively, and then perform the composition after the rendering is complete, in other words, the front frame and the back frame. Fusion, and NVIDIA's idea is very different, the method is to divide the single frame in the screen into several parts, if it is a two-way SLI, then the screen is divided into two parts, if it is three, four or even if it is the highest eight roads, so Each road is responsible for rendering a certain number of roads. More importantly, in later developments, NVIDIA improved the resource allocation problem in SLI technology. In other words, it achieved 3:2, 4:3, 5:3 single-screen segmentation. The goal is to ensure that the primary and secondary cards in the SLI system require consistent working time when working, because the primary card not only needs to render the components that need to be rendered, but also needs to allocate, direct, and control the tasks first, so the master card finishes rendering time. The secondary card is long, and then there is a secondary card waiting for the primary card to allocate the "free time" of the next frame. This problem is similar to the CPU performance we often avoid to avoid weak GPUs. Performance issues.

Mod edit - Unrelated link removed.
 

8350rocks

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You do realize that Nvidia bought 3DFX out, and literally plugged the 3DFX SLI into their GPUs, right? I mean, the only reason they can even call it SLI is because they bought the trademark, and the patent, when they bought 3DFX.
 
Feb 14, 2019
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hi people i got two rx 570s for a crossfire on an asus x399 with an amd 1900x in it . i can't seem to crossfire anyhow , i got two questions , first . what should i do to crossfire second is there a board with room for 4 amd gpu's (a non-mining board for gaming and such) .
 
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