quick question about the r9 290x vs 390x

happy medium

Lifer
Jun 8, 2003
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If I were to overclock the 290x to 1100 core 6100 memory @ 75c (no throttling) will I have the same game performance as a 390x ? AND do the cards have the same directx 12 capabilities/features?

Are there any meaningful differences in the two cards? besides 4gb vs 8gb.
I ask because I was thinking of buying a 290x. (cheap)

thanks
 

Actaeon

Diamond Member
Dec 28, 2000
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Yes, the chips are identical. The biggest difference is the memory capacity.

If you can get the 290X to the same clock speeds it will be about the same performance. However not all 290Xs may overclock to those settings. My Sapphire 290X got that high but I know not everyone else was able to.
 
Feb 19, 2009
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It's the same chip. AMD pulled a damn PR stunt by skipping the reference cooler and going straight to custom cooled variants. When they released it, I called it a stunt, didn't expect it to do well but I was wrong. People love the 8GB and "quiet and cool"....

At the same clocks, the performance is identical.

Heck, you don't even need to OC the vram, because hardly ANY game, is bandwidth bottlenecked by the beastly 512 bit bus.

My R290X at 1050mhz and 1250 vram has similar performance numbers to 390X in benchmarks. A few games increase by 1-2 fps with vram OC to 1500mhz, Crysis 3 was one, as well as GTA V. The rest, I didn't see a difference.

ps. There's no game where more than 4GB proves to be a difference in playable performance, even at 4K, not for single GPU, not for 2 GPUs.
 

happy medium

Lifer
Jun 8, 2003
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thanks guys.....by the way the model is a Sapphire tri- x, reviews seem positive.
This is one of the better 290x's correct?

I missed the whole gtx680/780/7900/290 era.
 
Feb 19, 2009
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TriX is one of two best R290/X. That thing is cool and silent.

The other is the Vapor-X, which actually comes in the 8GB edition, R290X 8GB aka 390X. :)
 

UaVaj

Golden Member
Nov 16, 2012
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same gpu. if 290x bothers u that much. you can flash it to 390x.
8gb is a waste. especially single configuration.
only reason to consider a 390x is for longer warranty reason.

as for noise. with a gaming load. they are all loud. rather that be reference or aftermarket.

if you get a reference. you must run an updated the fan curve. stock fan curve is piss poor.
 

Mercennarius

Senior member
Oct 28, 2015
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I've owned both and can tell you in theory at equal clocks performance should be 99% the same. But unfortunately many 290Xs do not have VRAM that can overclock high enough. My sapphire tri-x 290x 8gb had elpida VRAM and could never clock the RAM as high as a stock clocked 390x. My Sapphire 390X also seems to run a little cooler.
 

.vodka

Golden Member
Dec 5, 2014
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Yeah, a well cooled 290/X at the same clocks of a 390/X is going to have almost the same performance. The only condition in which one of these cards is going to have poor performance is if it's throttling... like in the reference blower of hell 290/X. Otherwise it's solid performance, closer to the 980 lately.

390/X reaches 1500MHz stock memory clocks due to different memory timings, otherwise the GPU is the same on both series. Hell, memory chips in the 290 series are usually 1500MHz capable (Hynix in particular, Elpida has it more difficult), the GPU's memory controllers aren't at such high speeds (relative to the 1250MHz it launched at). That got fixed in BIOS in the 390 series.


Gotta thank the stilt for his insight on these cards, in the BIOS modding threads all over different forums (especially OCN/G3D).
 

MrTeal

Diamond Member
Dec 7, 2003
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At the same clocks assumes core/vram..

Why not 100%?

Where's that 1% going?

It's the same chip. heh

The chip is the same, but the firmware and software are not.

I don't believe (and feel to correct me here) that the 2xx series GPUs get all the benefits that the newest ones do from a support aspect.
 
Feb 19, 2009
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The chip is the same, but the firmware and software are not.

I don't believe (and feel to correct me here) that the 2xx series GPUs get all the benefits that the newest ones do from a support aspect.

They do get the same driver support.

At the same clocks, the performance is identical unless 4GB vs 8GB plays in it, which I have seen zero evidence that it does, not at playable settings.
 

Actaeon

Diamond Member
Dec 28, 2000
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At the same clocks assumes core/vram..

Why not 100%?

Where's that 1% going?

It's the same chip. heh

I thought I read the memory timings were different between the 290s and 390s. I would consider that to be within the realm of 'noise' and it isn't enough to make a substantial difference but maybe that 1% he was suggesting :)
 

Madpacket

Platinum Member
Nov 15, 2005
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I could be wrong but the biggest benefit is having a more mature process for the dies so I imagine the yields are also better (better overclocking on air). Tighter memory timings (due to them ditching Elpidia memory) and I think you're practically guaranteed to get Hynix which is a plus. 8GB of RAM is a waste today but it may help out in odd corner cases (like etherium mining down the road) or when crossfiring the cards the fillrate of two cards may then be adequate to use all 8GB. Hard to say really if it'll ever be useful but it doesn't hurt the card and I doubt it adds a ton to the BoM. It's not like a buying a Geforce 730 with 4GB of DDR3 :D

Anecdotal but I've owned several reference launch day 290's (two turned into 290X's) which I've since sold but these cards needed higher voltage to hit the same clock speeds as my current MSI R9 390.
 

UaVaj

Golden Member
Nov 16, 2012
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8GB of RAM is a waste today but it may help out in odd corner cases (like etherium mining down the road) or when crossfiring the cards the fillrate of two cards may then be adequate to use all 8GB. Hard to say really if it'll ever be useful but it doesn't hurt the card and I doubt it adds a ton to the BoM. It's not like a buying a Geforce 730 with 4GB of DDR3 :D

even with quad 290x running at 5960x1080.
can barely saturate 4gb at "enjoyable frame rate."

if anyone's idea is to jack up setting (ultra level of SSAA+MSAA) simple to saturate vram to the point of stuttering. then even 8gb is not enough.
 

Mercennarius

Senior member
Oct 28, 2015
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I mentioned earlier a 290X is 99% equal to a 390X at equal clock speeds because having both I can tell you they are very close clock for clock. But the 390X does have better memory and can overclock higher than a 290X because of it. I could never even get my Sapphire 290X 8GB to achieve the stock clocks my 390X has and the 390X has a good amount of head room to go even higher. 390X Also seems to run a little cooler/quieter.
 

Madpacket

Platinum Member
Nov 15, 2005
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even with quad 290x running at 5960x1080.
can barely saturate 4gb at "enjoyable frame rate."

if anyone's idea is to jack up setting (ultra level of SSAA+MSAA) simple to saturate vram to the point of stuttering. then even 8gb is not enough.

Quad 290X's is just silly, most games don't scale past 2 cards very well. Many games won't even scale with two cards. Hawaii architecture does not have colour compression so the extra RAM could be useful but the more likely scenario is the card will be outdated before that amount of RAM will be necessary. However games may never use 8GB of RAM but they could easily use 4.1GB or 4.2GB and then what happens?
 

UaVaj

Golden Member
Nov 16, 2012
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Madpacket

even at this resolution. for "enjoyable frame rate". quad 290x is still not enough power to LOAD vram beyond 2.5gb. vram will eventually CACHE up to 3.5gb. even then. no where near 4.1gb.

so by the time anyone manage to LOAD up 4.1gb of vram. for sure frame rate will be choking. especially when most anyone is only running single gpu and some running dual gpu. both at much much less resolution.

not to mention a stout cpu is necessary to prevent any cpu bottlenecking.

so if anyone think they need more than 4gb vram for their e-peen. reason noted.



as for 290x scaling. extremely well on bf4 (when bf4 is not pms-ing). and butter smooth too.
 

UaVaj

Golden Member
Nov 16, 2012
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on another note.

vram sells so so so so well.
NVidia botched the 970's vram just so they could call it 4gb.
 

Headfoot

Diamond Member
Feb 28, 2008
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the 390/x are refreshes at a low level, some minor tweaks to slightly reduce power consumption at the higher clocks and they claim slight clock for clock performance improvements.

Anandtech said:
Last but certainly not least however, we want to talk a bit more about the performance optimizations AMD has been working on for the 390 series. While we’re still tracking down more details on just what changes AMD has made, AMD had told us that there are a number of small changes from the 290 series to the 390 series that should improve performance by several percent on a clock-for-clock, apples-to-apples basis. That means along with the 20% memory clockspeed increase and 5% GPU clockspeed increase, we should see further performance improvements from these lower-level changes, which is also why we can’t just overclock a 290X and call it a 390X.

So what are those changes? From our discussions with AMD, we have been told that the clock-for-clock performance gains comes from a multitude of small factors, things the company has learned from and been able to optimize for over the last 2 years. AMD did not name all of those factors, but there were a couple of optimizations in particular that were pointed out.

The first optimization is that AMD has gone back and refined their process for identifying the operating voltages of Hawaii chips, with the net outcome being that Hawaii voltages should be down a hair, reducing power and/or thermal throttling. The second optimization mentioned is that the 4Gb GDDR5 chips being used offer better timings than the 2Gb chips, which can depending on the timings improve various aspects of memory performance. Most likely AMD has reinvested these timing gains into improving the memory clockspeeds, but until we get our hands on a 390X card we won’t know for sure.
From: http://www.anandtech.com/show/9387/amd-radeon-300-series/3.

The testing I've seen shows that if there is a realizable IPC difference it is very minute. Though the power reduction @ the same high clocks thing seems to have panned out to be real, if small. The biggest change is the guaranteed higher clocked memory. My OG 2013 290 will literally crash if I increase memory speed at all. It has that garbage Elpida ram some 290s shipped with.
 

Madpacket

Platinum Member
Nov 15, 2005
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even at this resolution. for "enjoyable frame rate". quad 290x is still not enough power to LOAD vram beyond 2.5gb. vram will eventually CACHE up to 3.5gb. even then. no where near 4.1gb.

I guess we'll just have to agree to disagree here. 4 X 290X combined certainly has enough fillrate to game at 4K. Heck my dual Fury X's already can play most games comfortably at 4K with high detail so 4 290X's (if they could scale properly) would definitely be faster than 2 Fury X's.

Anyways, the point is kind of moot as we know anything more than 2 cards is a bit of a waste (even two cards are questionable) for many games. The issue of VRAM will resurface once we have single GPU's powerful enough to drive 4K gaming but then these cards will have HBM which as we know from recent testing 4GB is plenty.

I also suspect combined memory pools and non AFR rendering modes in DX12 will go a long way to resolve the multi card issue but it'll be a few years yet before DX12 is used everywhere. Another area that may take off though is rendering per eye in VR. AMD can dedicate a card for each eye so this could be an interesting use case for extra VRAM if combined memory pools aren't used at first.

Tought to say! Should be interesting to watch how it unfolds.