KickAssCop
[H]F Junkie
- Joined
- Mar 19, 2003
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The 780 Ti rapes.
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The 780 Ti rapes.
Question :
Can the 290(x) chip possibly be paired up with faster memory? With the ultra-wide bus this could make for a drastic speed increase, I'm curious if there may be a technical reason (TDP?), or is it just cost? (At which point it opens up further possibilities for AIBs)
. Go somewhere that is.
If you continue like this, I will report your posts.
It can be, but it's usually not the memory chips holding it back. AFAIK, all the Hawaii cards already come with chips rated for 1500MHz (6.0GHz effective). AMD simplified the memory controller to save silicon and that simplified memory controller is the limiting factor and the reason why many cards can't hit the memory speed their memory chips are rated for.
That is actually a really smart move by AMD since they are not bandwidth restricted as it is.
I can clock my ram faster than 6GHz with +100mV on the core.
I benched it at 1620MHz, 5MHz short of the maximum allowed on MSI Afterburner.
Quad pumped gives 6.48GHz.
It ran fine at this speed but when returning to idle voltages while the memory was still hot, my machine became a bit unstable.
So the memory overclock has to also be stable at the voltage set when idle, not just the load voltage.
At least with the XFX 290X bios I am using, I have a feeling the Asus bios has some differences.
And overclocking with CCC must be disabled because on reboot it will apply the high memory overclock but cannot change to a supporting voltage. Instant machine crash when CCC loads.
I had this problem and my only resolution was to reboot in safe mode, disable CCC, reboot, un-install driver, reboot, re-install driver.
So just to point out again.....when the cooling solution is sufficient and not hamstrung by arbitrary restrictions overclocked 290X has higher performance than overclocked 780ti....just get over it.
Prove it. If this information is widely available like you seem to be implying, it shouldn't be hard.
I don't think it is fair testing these cards at different fan speeds....the only way to fairly test them is with both with 100% fans regardless of noise.
You say there was no throttling as you kept temps below 94c....that is debatable, power tune alters settings in fractions of a second and if you looked at this microscopically you may well find that throttling is occurring.
Secondly your selection of a lower fan speed for the AMD card may well be affecting the maximum overclock you are achieving....I would say this is undoubtedly happening as you are hitting 90c....higher silicon temps mean greater leakage which means more voltage is required to be stable which means more heat...you have basically surpassed the ability of the cooling solutions effectiveness.....its a vicious circle which you have deliberately brought about in the AMD card not only by using less than 100% fan but also using a slower fan speed than the Nvidia card you are comparing it to.....how can you ever justify that when making a "fair" comparison.
Interesting indeed.
If I am understanding correctly the stock cooled 780Ti is beating the custom cooled 290X by a fair margin in BF4 & C4 when both are overclocked and after the "warm up period" when the 780ti is throttling back to 941MHz.
^^.....I see no reason or logic in comparing two cards when you use unequal settings.....if you are not going to use 100% fans on both...which you should in a performance test....this is a performance test not an acoustic test isn't it?....then at the very least use the same fan speeds on both cards, and no the author did not explain why he used a lower fan speed on the 290x than on the 780ti.....only why he didn't use 100% fan.
Running the 290x at 90c and the 780ti at 75c is ridiculous....the lower temp will obviously allow for a higher stable overclock....as I stated, whether you accept it or not, if adequate cooling is not an issue 290x outperforms 780ti
Question :
Can the 290(x) chip possibly be paired up with faster memory? With the ultra-wide bus this could make for a drastic speed increase, I'm curious if there may be a technical reason (TDP?), or is it just cost? (At which point it opens up further possibilities for AIBs)
Just google around for watercooled benchmarks....I don't have any to hand atm....but that was the take home message I got from reading several different ones.
Moving the fan to 100% did NOT change performance at 1115MHz. It added a whole lot of extra noise, with no performance benefits. Therefore, a waste.
That may be the case but you would have got a higher stable overclock at 100% fan speed.
The 290X having a smaller die size and so greater heat density is going to be very susceptible to reducing the cooling efficiency as you have done by limiting the fan speed.
Additionally running at higher temperature only increase the severity of that issue as increased silicon leakage at higher temps just leads to more power draw and more heat and less stability.
Don't miss understand me...even with these custom cooled solutions it may be that air cooling is simply insufficient to adequately cool this chip....but from what I've seen with water cooled benchmarks the overclocked 290X outperforms overclocked 780ti ie quite the converse to your findings here.
It would just have been nice to see a comparison of custom cooled 290X vs custom cooled 780ti at 100% fan just to see the all out winner.....as it stands this is just a comparison at some arbitrary and unmeasured sound level, circumstances that will most definitely favour the more easily cooled Nvidia chip.
Well this isn't an article about how well these cards could behave when water cooled. I doubt that you're going to see a review of water cooled cards here as just not enough people do it.
That may be the case but you would have got a higher stable overclock at 100% fan speed.
It would just have been nice to see a comparison of custom cooled 290X vs custom cooled 780ti
as it stands this is just a comparison at some arbitrary and unmeasured sound level, circumstances that will most definitely favour the more easily cooled Nvidia chip.
$699 at newegg... jesus christ. Will newegg include a cuddle after ass raping you with the 150 mark up?
It is not arbitrary. Nor does it favor one or the other. The ASUS card is not being held back in its overclock or its performance. This is about the 4th time I've said this now. I will not repeat it anymore.
Memory controller is not the issue.
Many Hynix chips based cards like Tri X for example are hitting 6000 + as average, few of them go to 7000....
Asus use Elpida crap, they dropped the ball this generation sadly.
This is true. Those other "reviewers" rarely test those quick oc's for stability as well.He predicted that the maximum overclock will be less than on other sites because [H] have spent a long time using the card and have made sure it is rock stable all the time.
Whereas most reviews will do a comparatively quick overclock test.
Haha.$699 at newegg... jesus christ. Will newegg include a cuddle after ass raping you with the 150 mark up?
Memory controller is not the issue.
Many Hynix chips based cards like Tri X for example are hitting 6000 + as average, few of them go to 7000....
Asus use Elpida crap, they dropped the ball this generation sadly.
Tried it. Apparently you did not read page 3.
I also tried 100% fan at 1.35v. End result, it did not.
I know that the amount of overclock can very but you seem to have a very bad sample there.
I have a Gigabyte 290X oc windforce (no not a fan boy just upgraded from my 2x gtx 460s which were great)
I can hit 1115mhz with a voltage increase of just +25 milivolts the core runs at about 1.170volts not the 1.35volts you are using...no wonder your thermals are through the roof.(in fact that vcore was good upto a clock of 1170mhz....so if I'd bothered to mess further with such a low overclock then I'm certain I could have cut that voltage down somewhat)
At those settings with 100% fan temps are 50c not the 90c you have...something is very wrong there.
I've got to 1210Mhz using the maxvoltage offset of +100mv which during use equates to a vcore of between 1.22-1.25volts.....temps with 100% fan are 61-65c so again your thermals and vcore are way not standard.
Having said that I'm at the limit now....I've tried reducing the % of fan speed but if temps go above 65c its not stable at that clock speed...so I may have to rein that in a little....memory clocks appear good at 1450 but haven't tinkered too much there yet.
I noted some anomalies whilst tinkering....I noticed that if you don't disable overdrive in CCC then power tune keeps dropping the voltage causing instability(even when using a separate overclocking tool).....may be why you felt the need to zap upto 1.35volts?
I downloaded the latest beta of MSI afterburner and selected "force constant voltage" on in the settings...the only variance of vcore then was due to v drop due to load.....seriously that card you tested is naf or your methodology isn't right for Hawaii.
These cards vary a lot. Bubbaboeyhtj has his 290x under water and he reached similar results as hardocp.
8-pac, who's a world class overclocker got the 290x to 1200mhz with 1.4 volts using a 4 slot air cooler.
Great review as always! Thanks for putting in the time.
Green means go, Red means...? I guess we'll have to wait for other non-reference 290X models to appear and see what creative implementations are instituted. If anything can be done to combat the sheer amount of heat being generated.
"Many" and "few" are the key words there. The typical Hawaii memory OC among end users seems to be around 1400 which is still lower than the 1500MHz that the Elpida chips are rated for. How is that not a memory controller limitation? Are you saying that most of the Elpida chips and even some of the Hynix chips are not able to hit their rated speeds?
Technogiant, your posts make me laugh. Here you are talking about "unfair" methodology but you have missed the glaring flaw in your argument; if you wanted to worry about fan speeds and make this "fair" we'd need to disable one of the fans on that custom 290x. I'm sure your fanboy heart would break seeing those test results, so why not just leave well enough alone? AMD got their asses handed to them. Maybe they'll have an answer next generation.
Move on.