HD6990 is dissapointing me

@AlienALX,

I'm quite surprised by your SLI comments. In my experience (GTX 570 SLI) I've yet to find a title that doesn't just work in SLI. Sure, I've had the odd (old old) title where I've had to manually set it to use SLI as the default profile didn't use it - but that's by far the minority. In fact, I cannot name a title I needed to do that on, I just recall doing it once.

Additionally, while no game scales at 100% of course, all get a huge boost. Crysis 2, which I thought was ok on one card became silky smooth on two. Skyrim - with my excessively modded version - plays lovely too, a huge boost over one card.

I actually did a fairly large post a year or so back about my very first SLI experiences - I was quite nervous after my friends constant problems with his 4850's then 4870x2's in Crossfire - but everything went so smoothly. I just popped the 2nd GPU (a newer rev 2 "HD" 570) with my original 570 (a rev 1 card, same PCB as a 580) connected the bridge, powered up the system, enabled SLI in the driver and I was done.

I'd assumed that today AMD cards in Crossfire worked equally as seamlessly, though I've no direct experience with Crossfire since the 4870x2 - well, quadfire using a pair of them actually - and they were pretty rubbish with constant glitches and reported "60fps" in benchmarks and games that looked more like 20fps! However, chatting to people here, I thought things had progressed hugely since then.

In my opinion AMD cards offer fantastic performance for the money, especially since the recent drivers gave the 7000 series a good boost. Conversely, my friends and I have noticed that recent NV driver updates have not really given much of an overall boost, but image quality and sharpness are MUCH better - I think this happened with the 310.* drivers and on, so not sure what they did.

Now, I have personally & when helping friends, had huge issues with ATI's drivers - yes, I mean "ATI" as they were ATI back then - with things not working, artififacting, crashing, using just one GPU etc. but I really thought that AMD (yes, them now) had gotten on top of all this.

I am a little NV biased, but purely based on repeated great experiences with their products. However I'd have no problem buying AMD & would happily put a pair of 7970's in my PC if my 570's died (please don't die 570's!!) & I'd expect them to just work, though likely I'd be a little nervous jumping camps which I think is understandable.

@OP - I tried to look up your PSU as it was not a brand I recognised, just to check its specs to see if it was up to the job of powering your system. However, I'm struggling to find any information on it. This makes me quite nervous! I really do think that a good, quality PSU should be the heart of every machine, especially that of an enthusiast. A poor PSU can be the route cause of a whole load of issues, from poor overclocking / base performance to crashing and system freezes, a good PSU is key, especially when using highend hardware.

I would seriously consider changing you PSU, I particularly like the Corsair range myself and have just ordered an AX860i for myself - in fact I'm listening out for the van right now :)

Scoob.
 
@AlienALX,

@OP - I tried to look up your PSU as it was not a brand I recognised, just to check its specs to see if it was up to the job of powering your system. However, I'm struggling to find any information on it. This makes me quite nervous! I really do think that a good, quality PSU should be the heart of every machine, especially that of an enthusiast. A poor PSU can be the route cause of a whole load of issues, from poor overclocking / base performance to crashing and system freezes, a good PSU is key, especially when using highend hardware.

I would seriously consider changing you PSU, I particularly like the Corsair range myself and have just ordered an AX860i for myself - in fact I'm listening out for the van right now :)

Scoob.

Other people on the web with 6990s are also having the same issue with AC3 from what I could tell
 
@SPS

Really? I didn't know that. I thought the 6990's were generally well respected for their X-Fire performance. Hopefully a driver / profile update or a game patch can address this as the card shold be more than capable.

Maybe the PSU concerns are a red herring.

Scoob.
 
@AlienALX,

I'm quite surprised by your SLI comments. In my experience (GTX 570 SLI) I've yet to find a title that doesn't just work in SLI. Sure, I've had the odd (old old) title where I've had to manually set it to use SLI as the default profile didn't use it - but that's by far the minority. In fact, I cannot name a title I needed to do that on, I just recall doing it once.

http://www.geforce.com/games-applications/pc-games

Have a look there. You will be amazed at how many games don't support it.

Then have a read of this.

sli-1.jpg


So whilst many who use SLI may think it is working and helping out it usually isn't.

It shocks and astounds me how many people fool themselves into things.

Yes, I run SLI, but I make no bones about it. At the end of the day hardly anything supports it and a bodge IMO (like FC3) doesn't count.
 
BTW I would say Metro 2033 scales at 100% given that my tests saw a 100% improvement in the minimum and maximum frame rates.
 
You know, EVERYTHING that I have that was in any way GPU limited has been hugely improved with SLI. When I removed a 570 for a while FPS in Skyrim tanked - I couldn't play it at my preferred setting any more, Crysis 2 (though I'd been ok with it previously) felt terrible as did a variety of other titles.

Less demanding games, so those a single 570 can readily cope with, don't get any boost of course (v-Sync) but nor do they run worse. All I get is both GPU's just ticking over. I have some games where the GPU's often sit at just 20% load each, so SLI is working, it's just not needed. This did mean that both GPU's ran cool and quiet - though I'm now on water so that's moot.

Most of the recent FPS titles I've played really benefit from SLI too, ok, I could turn the settings down on a single card and get a comparible frame rate, but I like turning things up AND keeping a good frame rate.

All I can say is that you've either had some bad luck with the titles you like to play, or you've managed to find a lot of exceptions.

Games I've been playing lately:

FC3 - MUCH better with SLI, but it does have it's issues - even with a single card.
Skyrim - nice steady 60fps most of the time in SLI with my (modded) settings, only high-30's with a single card which make it unplayable (at those settings) for me.
Crysis 2 - super smooth and fluid feeling in SLI, need to turn down a few settings to get even close with a single card.
Starcraft 2 (yes, I was late to this one lol) despite being an RTS, it's quite demanding. SLI, combined with a CPU OC made the game feel a lot more fluid.
WoW - I was into this for a while and SLI let me turn the setting right up, making WoW really quite pretty, while maintaining a solid 60fps.

I've not played Metro 2033 lately, but that did give a huge boost and was one of the first titles I tried out. Also, Fallout 3 with some tweaking played lovely in SLI - though it's been a while...possibly I'm thinking FO3:NV.

So, overall, I've been very pleased indeed with my experiences using SLI. In fact, unless something really special comes along, I'll be going dual GPU on my gaming rigs from now on. I'm not one to spend money for the sake of it, but I do like a good gaming experience.

Note: I, like many, use v-sync to lock me to 60fps. Only with SLI have I managed to get the games I play sustain 60fps with higher settings. I usually only use 4xAA though as any more is largely unnoticable yet hits the FPS hard - that's where more vRam might help, but the visuals aren't worth it.

To reiterate, every game I've tried that is in any way GPU limited has benefited from SLI. Most just work, no action needed, with the odd rare title simply needing it turned on in the profile.

Edit: I did read the scanned article & I think they are largely talking rubbish. They go on about profiles and the like as if they are the be all and end all of SLI working at all. This simply is not the case in my experience. I've used older drivers with new games and had performance that's just fine, still much better than a single card. Ok, NV do often release Betas to add specific support / improvements to certain games - this is great, and I do like to keep my drivers up to date regardless. However, I cannot recall the last time I had to take specific actions to get a game working in SLI and benefitting from it. The BIG thing that impressed me most about SLI was how it just worked. This was in contrast to my friends experience with his 4870x2's where he's spend ages configuring and tweaking stuff, and even then he usually ended up disappointed. That's why he replaced his 2x 4870x2's with a pair of GTX 480's and has never looked back. In that respect the article is spot on, as he was never happy. After my experiences with SLI I assumed things had moved on, plently of X-Fire users commented that their experiences mirrored mine in my SLI thread.

Scoob.
 
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That's the thing really, I've never checked any of my games to see if they're on some list as officially supporting SLI, as everything I've tried just works. If I did encounter a problem I'd be sure to chase it up online of course.

Possibly I've just been lucky with the timing of my purchases. I think Skyrim is the only game I had on day one, most others I pick up a while later at a discount...yes, I'm tight lol.

Scoob.
 
That's the thing really, I've never checked any of my games to see if they're on some list as officially supporting SLI, as everything I've tried just works. If I did encounter a problem I'd be sure to chase it up online of course.

Possibly I've just been lucky with the timing of my purchases. I think Skyrim is the only game I had on day one, most others I pick up a while later at a discount...yes, I'm tight lol.

Scoob.
If it's not needed I would not buy a new PSU.
info: http://www.recom.nl/psu.html
Pose if I won't OC, than do I need a new PSU when running a GTX680, and in future SLI?
 
Thanks for the spec sheet link...

I'm a little confused by the information though as it seems to contradict its self:

"One Single +12V Rail (max. 730watt)"

then a little later:

12v+1 912w max

The former is a little less than my Corsair HX750 PSU, whereas the latter is more what you'd expect from a 1050w PSU.

If the former is true, then this would be the equivant of a fairly average 750w. 730w on the 12v rail, considering that 12v is for CPU, motherboard and GPU's would be pushed if you were to overclock with SLI/X-Fire potentially. Note that higher load couple be within PSU limits, but there is a risk of additional noise (electrical) at such loads.

I don't think it's a bad PSU as such, and I hope it'd be just fine for your needs at stock, but the discrepancies would put me off. Not meaning to worry you at all, just saying what I think - I'd not buy that PSU myself. Nor do I think it has a place in an enthusiasts machine, again just my view. Anyone else have any experience with these Recom units? I think we'd benefit from some testimonials here.

Scoob.
 
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