PCI-E Bandwidth?

The current motherboard i have (Asus M5A97 R2.0) supports x16 x4.

I was just wondering if i could run two 2GB 7850's overclocked in the curent set up. If not could somebody please reccomend a motherboard capable of doing so (if at all possible).

Motherboard specs as per Asus's site

http://www.asus.com/Motherboard/M5A97_R20/#specifications

PS: If anyone is wondering why i have a 7850 vs a 7870 its because i got the 7850 dirt cheap in a sale.

 

 

You will take a performance hit (~10% if I recall correctly), but it's doable. 4 lanes of PCI-e 2.0 is the bare minimum for CrossFire with mid-range GPU's. Tom's Hardware had an article on this when Sandy Bridge first came out due to the lack of PCI-e bandwidth the 1155 platform has, but I can't find it ATM.

Actually the impact is not to bad i have actually tested this internally an example is results on a M5A99FX PRO R.20 ( which supports full PCIe lane Crossfire )

Sniper V2 with 7770

optimal x16 x16 configuration approx 32FPS

Running in Primary 16 x4 configuration was slightly reduced to approx 30FPS

The bigger concern which i have not fully tested is how it might impact latency due to the reduced bandwidth. Assuming this hold consistent and the maturity of the graphics driver is solid for the game you are playing you should actually be ok.

I will see if i get time to retry with 7850 GPUs if i have any. keep in mind though that as you go to higher performance GPUs and go Crossfire a higher frequency and higher core count can help to ensure better consistent performance and minimize latency issues.

Hope this helps. Enjoy the rest of your day.

Thanks for the info guys.

My friend wants a 7850 and i offered to sell it to him as i only brought it a month ago for just slightly under the price of what i bought it.

 

My question is, what 7870 do i get? Id really like to it be quiet and have 2 DVI inputs.

I was thinking the Sapphire 7870 Flex : http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1160&lid=1&pid=1627&leg=0

Sapphire, ASUS, Gigabyte, HIS and MSI have some really nice 7870's 

But for the best cooling and noise performance get either the ASUS or the Gigabyte, as their coolers are neck and neck and everything else is behind them in terms of either cooling or noise.

Thanks alot for the help guys, but i have decide to put a bit money in for future proofing and im going to get a 7950 because there is a sale on at around £20 off.

I take it the Asus 7950's are also really good? If not im looking at the XFX 7950 DD.

The Asus 7950's IMO arent good because of the Triple slot design, Gigabytes 3 Fan Windforce is awesome and is cool and quiet, the Asus cards are good but really bulky, plus ive seen quite a few Gigabye 7950's overclock like monsters, also consider the Gigabyte has 100Mhz on the core clock of the Asus as stock.

Overall we designed the triple slot design as it provide the best way to maximize thermal dissipation and also ensure very low noise. The reality is that 90% of the market only uses one gpu so we feel through the design research providing superior cooling and acoustics is a better choice.

In regards to your questions on the 7950 they feature all the same updated PCB and VRM components. So you will get a great performance experience in both gameplay as well in regard to thermals and acoustics.

One nice additional option on our cards is our dust proof fan design it is a double sealed internal hub that elminates dust and debris and dander from getting inside the huib assmebly and can cause the fan to fail or have impacted rotation performance.

Hope this helps. Enjoy the rest of your day.

Yeah ASUS 7870 DCII is a sweet card check out the thermals even when overclocked OC. Additionally the RPM curve in combination witht he high disippation abilites really due keep th ecard cool and quiet.

The card used is already overclocked as it is the TOP edition but keep in mind that the not TOP ( or standard ) 7870 DCII V2 all feature the same exact cooler and heatsink assembly, non reference PCB and custom Digi+ VRM and SuperAlloyPower power implementation.

 [URL=http://imageshack.us/photo/my-images/94/7870temps.jpg/][IMG]http://imageshack.us/a/img94/1229/7870temps.th.jpg[/IMG][/URL]

[URL=http://imageshack.us/photo/my-images/202/7870oc.jpg/][IMG]http://imageshack.us/a/img202/6517/7870oc.th.jpg[/IMG][/URL]

 

Hope this helps. Enjoy the rest of your day.

I was wondering kinda the same thing because I stil have my Intel core 2 quad system and want to upgrade that as a better gaming PC for when DayZ standalone comes out because right now I am getting 20-23FPS max in the mod as is and arma 2 is no better, I knwo both these games are mostly CPU dependent but to play with better graphics I need a better graphics card (I have a GT210 right now) and all I have is a PCI-E 1.1 x16 slot on my motherbaord so would I be able to put like a GTX650ti in there? I saw something about it a while back that the bandwith is good enough for PCI-E 3.0 but I am not sure any of you could help that would be great.

Heres a review of the Gigabyte with a really high OC, part of this is the great VRM cooling thats introduced with the 3 fans.  

http://www.vortez.net/articles_pages/gigabyte_hd7950_windforce_review,9.html

and here's the reason to stay away from the triple slot ASUS 

Seems like there is not enough contact and the custom VRM design they used is overheating/inefficient.

http://www.overclock.net/t/1220328/behardware-asus-hd-7950-directcu-ii-fault-report 

 

Definatly looking at the Gigabyte and the XFX DD, thanks a lot guys

The XFX DD isnt that good at cooling and the VRM's can get pretty hot, go Gigabyte, Sapphire or MSI for the 7950's

The M5A97 isnt awesome by any means. Its a great mid level (meaning its not mid level but gives good performance) board that has a crappy 2nd PCIe pipe. It works.

I have had 3 of these (1 I have in my own main rig) and havnt had 1 fail yet...even for a customer that wanted (and got) an 8350 OC'd to 4.6 with no issues.

I would not recomend this board for that kind of reliable performance though. It just doesnt have the heatsinks for it.

Thanks ill take a look at how loud the gigabyte is!