AMD chipset and Xfire

[phishy714]

I have a quick question regarding AMD chipsets and the Xfire technology. This has more to do with what motherboard I am going to upgrade to once Bulldozer comes out, but basically, I am looking at my current mobo (ASUS M4A88TD-V EVO) that says it is CrossFire ready. So I guess I can just get another card (of course same type of card), get the correct drivers and i'm good to go for the most part.

However, looking at the chipset on this mobo (880G), the description doesn't say that it supports Xfire technology like the 890's say they do. Hell, looking at the amd website (http://www.amd.com/us/products/desktop/chipsets/8-series-integrated/Pages/amd-880g-chipset.aspx) it says that the card supports 1 card. Obviously, one can Xfire on this board, so what exactly does this description mean?

This brings me to the AM3+ boards with the "new" 970 and 990 chipsets. The 970 says "◦PCI Express® 2.0 technologies enable 1x16 graphic boards for a great everyday computing experience" which makes it sounds like it won't support Xfire, while the 990x and fx version clearly state their xfire feature.

So... what does this mean? lol Sorry if im a bit of a noob on this.

 

[jaquith]

The ASUS M4A88TD-V EVO/USB3 is not a great choice for Crossfire especially on an x4 PCIe, and it's an AM3 and NOT an AM3+. The ASUS M4A88TD-V EVO/USB3 has on onboard iGPU and is really meant for 'Hybrid-Crossfire' which ties a low-end discrete AMD/ATI GPU to the iGPU. Further, AM3+ is required for a 'Bulldozer' CPU.

The 970 e.g. ASUS M5A97 EVO x16/x4 wouldn't be my pick for CF and maybe 990X x8/x8 in CF. If you have a high-end AMD/ATI GPUs then I would recommend the 990{FX} with x16/x16 or x16/x8/x8 3-WAY. Another advantage with the 990FX is that it can SLI. Using today's GPUs you don't want less than x8 {8 PCIe lanes} to ANY GPU(s). There's a current limit of 4 GPU cores total.

All of the MOBO's support Crossfire, AMD opted for a lower-minimum for CF than SLI in other words if you have a free PCIe x4, x8, x16 it's good to run CF no BIOS 'locking'. nVidia didn't have this caviler approach and x8 is the minimum and the CPU must have at least 16-lanes for the GPU(s); it does this by a BIOS Key licensed to the MOBO manufacture per MOBO specs.

However, it's best to go to the MOBO's manufacture site and verify.

 

[phishy714]

Answered a question I didn't ask.. but ok..

I know my mobo is not AM3+, but I guess you did answer very very indirectly that chipsets govern how many x16 pci-e slots are on a card.

Guess i need to spend some money on mobo's that have a x8/x8 design for xfire. I hear the upgrade to x16/x16 is very minimal at best and not worth the extra premium you spend for that feature.

 

[jaquith]

A "Yes" or "No" does nothing to help you understand unless the answer is clear. I feel it is important to understand 'Scaling' and Crossfire. A quick question followed by 3-paragraphs doesn't seem so 'quick'.

Buying a MOBO it's important to understand the chipsets, how they impact performance, and justification for expense.

IMO - Buying ahead of a new CPU has it's drawbacks...wait until the Bulldozer is released otherwise you're a Guinea Pig.

 

[phishy714]

Oh I agree. I am not going to buy an AM3+ case right now. I was just looking at what an AM3+ mobo would cost me considering what I want to get out of one. I am definitely going to wait for Bulldozer to come out, mostly because I am sure that some companies will jump on the bandwagon and offer group discounts and stuff. Plus, you will get sites like Tom's to test out and review the chip along with some mobo's for it.

I was mostly looking as to what the different chipsets do and affect what the mobo can and can't do. You did answer my question in that way: the lower end chips don't support x8/x8 or higher pci-e 2.0 configurations. Only x16/x4, which seems to waste alot of the potential horsepower of an CrossFire setup. Also the fact that 9-series chips allow you to SLI on an AMD board.

Aside from those, and the fact that i'm sure higher end chips will allow you to overclock stuff better, is there any other BIG difference between the chips?

 

[jaquith]

If you mean examples like 890FX vs 990FX then no, not really aside the fact of SLI support. Good article -> http://www.hardwareheaven.com/reviews/1183/pg10/asus-rog-crosshair-v-formula-and-msi-990fxa-gd80-motherboards-review-990fx-vs-890fx.html the gains from the chipsets themselves have be more 'evolutionary' than massive gains. Obviously, x16/x4 vs x8/x8 or x16/x16 has the largest gaps in CF performance, but x8/x8 vs x16/x16 is minimal.