Widescreen Gaming Forum

Hey everyone,

I'm new here and was wondering if I could ask some advice...

I've recently just got an eyefinity rig together. I already had a pretty decent PC, as Im a programmer and do a fair amout of work from home - I wanted to do this for as smaller budget as I could get away with, so I invested in 3x (second-hand) 22" LG VGA monitors and an ATI 6870 1GB.

I have it all running and works cool on games such as call of duty 4 / GTA IV. My issue is this: the main game I play is Battlefield 3, which is pretty GPU intensive - my 6870 just doesn't cut the mustard I'm afraid. On low video settings Im getting 20 - 35 FPS, which is totally unplayable. Works fine on a single monitor on high settings at approx 55 FPS.

To further complicate my issue, my MOBO has dual GPU slots in the form of 2x PCI-e x16 slots, but one of them will only run in x4 mode, so from doing a bit of research, the general consensus is don't try and run crossfire... I read somewhere that best case I could expect +20% performance, worst-case is actually a performance hit.

So I'm left pondering my choices! As I want to do this as cheap as possible, I loathe the thought of overhalling the MOBO! Will a single 2GB radeon get me to a playable state in BF3 on low graphics settings? Or should I just give up and swap out the MOBO etc?

Any advice appreciated,

Andy :D

_________________
AMD Phenom II 560BE - running as X3 @ 3.5Ghz

ATI Radeon 6870 1GB

3x LG W2242S 22" monitors

12GB Corsair vengeance DDR3 @ 1600Mhz

120GB Corsair Force 3 SSD

1.5TB SATA2 storage

Focusrite Sapphire pro 10/10 firewire soundcard

Hey everyone,

I'm new here and was wondering if I could ask some advice...

I've recently just got an eyefinity rig together. I already had a pretty decent PC, as Im a programmer and do a fair amout of work from home - I wanted to do this for as smaller budget as I could get away with, so I invested in 3x (second-hand) 22" LG VGA monitors and an ATI 6870 1GB.

I have it all running and works cool on games such as call of duty 4 / GTA IV. My issue is this: the main game I play is Battlefield 3, which is pretty GPU intensive - my 6870 just doesn't cut the mustard I'm afraid. On low video settings Im getting 20 - 35 FPS, which is totally unplayable. Works fine on a single monitor on high settings at approx 55 FPS.

To further complicate my issue, my MOBO has dual GPU slots in the form of 2x PCI-e x16 slots, but one of them will only run in x4 mode, so from doing a bit of research, the general consensus is don't try and run crossfire... I read somewhere that best case I could expect +20% performance, worst-case is actually a performance hit.

So I'm left pondering my choices! As I want to do this as cheap as possible, I loathe the thought of overhalling the MOBO! Will a single 2GB radeon get me to a playable state in BF3 on low graphics settings? Or should I just give up and swap out the MOBO etc?

Any advice appreciated,

Andy :D

At worst with a x16 and a x4 slot you would look at losing 5% performance from a x16 and x16 config. You will not only gain 20%, or lose performance. You should notice a big step up.

However, IMO 6870 crossfire wouldn't be worth much more FPS, if you want to get playable at 3x1080p, you will require more GPU muscle. I would start by selling the 6870 and getting a 6950 2GB (THIS IS VERY IMPORTANT!!!!). I would also make sure your PSU is up to the job of running a 2nd card, and get another card when funds allow. I have no idea how much more performance you will gain from a 2nd 6870, maybe 70% more at best? So your 20-35fps probably wouldn't be playable still.

_________________
P8Z68-V Pro | 2600K | HR02 | HD5850 | 2x4GB Vengeance LP | 128GB M4 + 6TB | X-Fi > HD595 | AX850 | Tai Chi | PB278Q | G110 + Deathadder 2013
P8Z77-V | 3570K | Mugen 2 | HD5850 | 2x4GB Vengeance LP | 500GB | X-750 | Fractal R3 | U2212HM | G110 + G400
P8H77-I | G860 | 4650 | 2x2GB XMS | 320GB | CX500 | Prodigy | T22B350EW | MX518
DC3217IYE | 1x4GB Vengeance | 64GB M4 | TX-42VT20E

I would start by selling the 6870 and getting a 6950 2GB (THIS IS VERY IMPORTANT!!!!)

I would also recomend that!

If you buy a 2nd HD6870 1GB you're still limited on 1GB Vram, even though you have Nice Performance in GPU Power.
IF you buy a 2nd HD6870 2GB.... you get extactly the same result as if you bough a 1GB! Cant use 1GB+2GB in CF ;)

So a HD6950 2GB Would be next cheap option which gives noticeable performance increase! There would be no big difference to a HD6970... so that would be useless.

Next step would be a HD7970, but they're hella expensive!

_________________
We gonna send it to outa space!

Thanks for the advice.

I think that confirms a number of the thoughts I had. I appreciate the advice about running crossfire in X16 / x4 mode - I did find it difficult to get specific information on how much of a load i'd be placing the PCI BUS under -ie if the x4 would bottle-neck the potential capacity of the second card by a large factor or not.

make sure your PSU is up to the job

It isn't at present. I have a 650W corsair, which is probably already under a reasonable load (though I haven't been on a calculator for a while). So thats another cost.

Cant use 1GB+2GB in CF

-That I did not know and I'm glad you mentioned it.

I'm aware that it's a very subjective question, but in your opinion would a single 6950 2GB be able to produce something that is at least playable in the mean time? Say nearer the ~50 FPS region on BF3 -even if my graphics settings have to hit rock-bottom until I get a second card and run XFire?

Because, if there is a real possibility that it still won't be playable despite an upgrade to a 6950 -I then still have to upgrade my PSU and add a second 6950, in which case, it may actually be cheaper to consider a 7xxx series in the long run!


Thanks again guys,
Andy

_________________
AMD Phenom II 560BE - running as X3 @ 3.5Ghz

ATI Radeon 6870 1GB

3x LG W2242S 22" monitors

12GB Corsair vengeance DDR3 @ 1600Mhz

120GB Corsair Force 3 SSD

1.5TB SATA2 storage

Focusrite Sapphire pro 10/10 firewire soundcard

Depends on the model of the PSU, some of the corsair 650w ones are hefty. Which model is it? It may be fine to get a 2nd 6950 first, and upgrade the PSU second.

You are probably going to notice reasonable frame rate with a 6950, it will be more than what you have now, but how much I don't know. According to THG Graphics Hierarchy, the 6870 scores 77, the 2GB 6950 scores 95, so it is of the order of 30% faster, so you could guess your 20-35 would go to 26-45 FPS, give or take. Of course, if you were anywhere near your VRAM limit, the new card should fix that, and therefore I will not say you would only notice 30% increase.

You are always going to be in this boat, at this very second buying the absolute latest hardware is the best idea, however, next generation will knock the pants of it, and so on and so on. People with 3 screens need a lot of GPU power, so hefty GPU's come with the territory, but really 1 step down from the bleeding edge is the only economic way to do it, IMO. (I am not made of money!)

Just out of interest, a 7970 got a score of 168, whereas 6950 crossfire scores 200, so you are looking at better performance with crossfire, although bear in mind that you are also looking at more power draw and you will be at the mercy of AMD's driver team for new release games :)

_________________
P8Z68-V Pro | 2600K | HR02 | HD5850 | 2x4GB Vengeance LP | 128GB M4 + 6TB | X-Fi > HD595 | AX850 | Tai Chi | PB278Q | G110 + Deathadder 2013
P8Z77-V | 3570K | Mugen 2 | HD5850 | 2x4GB Vengeance LP | 500GB | X-750 | Fractal R3 | U2212HM | G110 + G400
P8H77-I | G860 | 4650 | 2x2GB XMS | 320GB | CX500 | Prodigy | T22B350EW | MX518
DC3217IYE | 1x4GB Vengeance | 64GB M4 | TX-42VT20E

Hey thanks again,

I totally agree about the 2GB of VRAM. Likely it will make enough of a difference to make it playable for now.

Its a Corsair TX650. It's already running a fair amount of gear:

3x SATA II HDDs,
1x SATAIII SSD,
AMD Phenom II 560BE, unlocked, OC'd
12GB (3x4GB Corsair vengeance @1600Mhz)
HD6870,
4x 120mm fans,
DVD Drive,

I also have a pretty heavy duty rackmounted audio card - which will drain the juice a bit. Though I can run that from a wall-wart if necessary.

-I ran a calc which reakons I'd be running aprox 596W of Juice with 2x6950's. On a 650W, I reakon thats pushing my luck a bit - 91% usage.

Cheers,
Andy

_________________
AMD Phenom II 560BE - running as X3 @ 3.5Ghz

ATI Radeon 6870 1GB

3x LG W2242S 22" monitors

12GB Corsair vengeance DDR3 @ 1600Mhz

120GB Corsair Force 3 SSD

1.5TB SATA2 storage

Focusrite Sapphire pro 10/10 firewire soundcard

If it is not too old (capacitor degradation) running at 90% capacity should be okay, if you could replace it within a short time frame. But safest would be to get another PSU first, of course :)

_________________
P8Z68-V Pro | 2600K | HR02 | HD5850 | 2x4GB Vengeance LP | 128GB M4 + 6TB | X-Fi > HD595 | AX850 | Tai Chi | PB278Q | G110 + Deathadder 2013
P8Z77-V | 3570K | Mugen 2 | HD5850 | 2x4GB Vengeance LP | 500GB | X-750 | Fractal R3 | U2212HM | G110 + G400
P8H77-I | G860 | 4650 | 2x2GB XMS | 320GB | CX500 | Prodigy | T22B350EW | MX518
DC3217IYE | 1x4GB Vengeance | 64GB M4 | TX-42VT20E