Mr. K6's 6950 -> 7970 Overclocking Review

[MrK6]

All the numbers are crunched and the graphs are updated, I just need to make it pretty. There's some interesting data there. First, there's no doubt this card has tremendous muscle, especially once overclocked. I think the BF3 graphs are most telling - the 7970 absolutely dominates BF3. You can also see how Skyrim is very CPU limited - no matter what, that benchmark averages about 45 FPS due to the constraints of the CPU and will not go higher. The Witcher 2 was also meeting it's 60FPS cap at 1080p, and seeing the game at near 60FPS with everything cranked at 2560x1600 is awesome. I'll try a run later with Uber enabled just to see what the 7970 can do.

One interesting thing to look at is how well the overclocking scales. Going from 925MHz -> 1300MHz is a 40.5% overclock. In Witcher 2, it seems to compound with the vRAM overclock to give a 55.2% performance increase. However, across the board it's generally less, in the 25-30% range. Considering that the GCN architecture was supposedly more efficient, I'll postulate that drivers are the cause of loss in performance here. It will be interesting to see how GCN-based cards improve over the next few months.

More to come :thumbsup:

 

[Skurge]

Excellent work, a lot better than some of reviews going around the web.

This makes me wonder if the rumors of the 1335mhz atomic sapphire are true, how the hell they managed an overclock like that on a (presumably) air cooler.

 

[Makaveli]

1000+ wasn't what people were looking forward to.

They were looking forward to a chip that responded to voltage allowing greater clocks than the 1125 every reviewer seemed to get on stock voltage.

And this is part of the problem and the reason AMD has clocked it at 925.

Expecting the same results was a fail before you started.

Nothing is guaranteed when it comes to overclocking.

Excellent thread OP!

 

[Elfear]

Thanks for all the work OP.

I got my waterblock today so I should have some results up tonight or tomorrow. Probably won't be as comprehensive as yours though.

 

[Concillian]

Use the skyboost mod for Skyrim if you want to remove a significant amount of the CPU limitation. Mod authors basically optimized code that Bethesda didn't bother doing in their port. 2 guys in a few weeks of spare time were able to raise framerates in CPU limited areas by as much as 50%.

viva la console port =/

You'd think they might hire these guys as consultants on their next console port. They did this one for free, they'd probably work on the cheap.

 

[MrK6]

Excellent work, a lot better than some of reviews going around the web.

This makes me wonder if the rumors of the 1335mhz atomic sapphire are true, how the hell they managed an overclock like that on a (presumably) air cooler.

Thanks :thumbsup:. It's tough to say. The possibility is there, I think, with a revised process and careful binning. However, both of those will cost time and money, which will undoubtedly be transferred to the consumer. We may be back to $600+ single-GPU cards.

And this is part of the problem and the reason AMD has clocked it at 925.

Expecting the same results was a fail before you started.

Nothing is guaranteed when it comes to overclocking.

Excellent thread OP!

Thank you and exactly, you can't expect it. If I had stuck with the XFX, there's no way I would have hit 1.3GHz. It's all in the luck of what chip you get.

Thanks for all the work OP.

I got my waterblock today so I should have some results up tonight or tomorrow. Probably won't be as comprehensive as yours though.

I'd very much like to see your results :thumbsup:

Use the skyboost mod for Skyrim if you want to remove a significant amount of the CPU limitation. Mod authors basically optimized code that Bethesda didn't bother doing in their port. 2 guys in a few weeks of spare time were able to raise framerates in CPU limited areas by as much as 50%.

viva la console port =/

You'd think they might hire these guys as consultants on their next console port. They did this one for free, they'd probably work on the cheap.

The sad thing is, I AM running SkyBoost R3 D:. Simply put, the code is "good enough" so that people get playable framerates at stock settings, so Bethesda probably doesn't give much thought/care beyond that. Always remember that the bottom line is the bottom line.

 

[blackened23]

Mr. K, I need some mentorship. I've never done water before, how expensive is it and what parts/resources do I need to get my hands wet so to speak?

 

[blackened23]

OMG.

BF3 1080p ultra at over 100fps.

Holy crap.

BTW, I see that Witcher 2 and Skyrim both scale negatively with your overclock - could you have some memory correction going on there? Might want to determine if that OC is completely stable.

Witcher 2 scales fine, you have to use the AMD 1/9 web driver. I get double performance with both GPUs at 99% in witcher 2. I was running around the forrest in Act 2 at around 120 fps at ultra, no ubersampling. (2560x1440)

Skyrim, not sure.

 

[Qbah]

Sick sick numbers. The jumps in BF3 and Crysis 2 are mind blowing... :awe: Thanks for sharing all your results!

 

[MrK6]

Sick sick numbers. The jumps in BF3 and Crysis 2 are mind blowing... :awe: Thanks for sharing all your results!

Glad to! :thumbsup:

Witcher 2 scales fine, you have to use the AMD 1/9 web driver. I get double performance with both GPUs at 99% in witcher 2. I was running around the forrest in Act 2 at around 120 fps at ultra, no ubersampling. (2560x1440)

Skyrim, not sure.

Skyrim is a CPU bottleneck, Witcher 2 is the 60FPS cap in the game.

Mr. K, I need some mentorship. I've never done water before, how expensive is it and what parts/resources do I need to get my hands wet so to speak?

Lol, gladly :thumbsup:. My approach to designing any computing solution is to come up with a ballpark budget and chose the parts to fit it. I value function over form, and tend to build "bang-for-your-buck" setups. That's why you see I use $0.49/foot Masterkleer tubing and $0.30 hose clamps on $2.50 clearance Bitspower barbs as opposed to $1.50+/foot Tygon tubing with $6.00/piece compression fittings; simply put, it gets the job done. On a side note, I think that's why many people think water cooling is more expensive than it actually is, as these little "bling" add-ons really do add up, but I digress.

My entire loop looks like this:

The flow is Swiftech MCP350 pump w/ XSPC Acyrlic top -> XSPC RayStorm CPU block -> MCR220 radiator -> Swiftech MCW82 GPU Block -> XSPC RX240 radiator -> Y-fitting -> pump. This whole setup cost me ~$300-350 dollars for absolutely everything. If you think about it, that's really not that expensive when compared to a high end air or pre-built water cooler for the CPU (~$80) and an aftermarket GPU cooler ($50+). Furthermore, if you buy some things used, you'll save even more (personal plug, I'll be selling my MCW80 GPU block and XSPC Rasa CPU block as soon as I clean them up, PM me if you're interested). I planned out this loop specifically for the CM 690 II case and bought the case with the intent of building this water cooling setup. This is because I like a clean look on the outside with all the water cooling components on the inside (except for the fill port). The design is a simple, robust solution. 7/16" Masterkleer hosing on 1/2" barbs create an extremely tight seal, and the hose clamps are there just for peace of mind. This loop is very low restriction with MCW82 now, so flow is excellent. This allows me to stick with the very quiet MCP350. Note that your pump is going to be the noisiest part of the loop, so isolating it from the case is the way to silence. You can see in my picture that I've suspended the pump in a cradle made with a big rubber band, which is the best solution I've found so far. My water is pure distilled water + PT Nuke and two .999 pure silver coils for biocidal activity.

Think about what you want to cool - I would go both CPU and GPU, building separate loops or only going GPU is a waste since cooling the CPU is as easy as adding another block to the loop. Are you cooling your GTX 580's or another card? Then figure out your budget. Finally, figure out your design, which I'll be glad to help with, which will depend on all of the above and the case/environment you'll be using them in.

 

[Bobisuruncle54]

Great advice there, makes me tempted to go full water myself! :thumbsup:

Can't wait for the results also. My 6950s put up a good fight but I'd much prefer a silent 7970 if I could get it to 1.3Ghz, might buy the Sapphire Toxic if that datasheet turns out to be true.

 

[BallaTheFeared]

Lol, gladly :thumbsup:. My approach to designing any computing solution is to come up with a ballpark budget and chose the parts to fit it. I value function over form, and tend to build "bang-for-your-buck" setups. That's why you see I use $0.49/foot Masterkleer tubing and $0.30 hose clamps on $2.50 clearance Bitspower barbs as opposed to $1.50+/foot Tygon tubing with $6.00/piece compression fittings; simply put, it gets the job done. On a side note, I think that's why many people think water cooling is more expensive than it actually is, as these little "bling" add-ons really do add up, but I digress.

Ha, I do the same, I never even spent money on a case

I have the same cheap tubing and BP fittings, never even bought clamps I just use 3/8ths tubing on 1/2 barbs.

I actually started this loop with the cheap $120 Rasa Kit and expanded it using all the parts from the kit.

It's nice to be cheap, makes the performance we get that much sweeter over those crazy priced Alienware rigs people brag about lolz.

 

[wahdangun]

wow, totally sick dude, although i think you water loop look really hideous, i mean the water is yellow O_0

 

[Termie]

OP - you might find this article on the XFX HD7970 DD interesting: http://www.hardocp.com/article/2012/01/24/xfx_r7970_black_edition_video_card_review/1

They used Trixx to overclock/overvolt. Did you try that approach? Although they had Afterburner running to monitor voltage, they didn't use it for overclocking.

That being said, the overclock they achieved was not impressive - 1150 on the core.

 

[spinejam]

Nice work-up MrK6!

7970 is certainly beastly when overclocked.

This is my xfire Asus 6950 DCII @ 6970 DCII bios:



Uploaded with ImageShack.us

 

[lavaheadache]

2600k @4.4
7970 @1300