AMD Zen 2 (Refresh) 3900XT/3800XT/3600XT

[Grim5]

Clock speed is not what is holding back gaming performance on ryzen.

I remember watching a video where they managed to overclock a ryzen 3000 chip to 5ghz to run some gaming benchmarks and it barely showed much improvement in framerates.

They concluded it was latency that holds back the performance the most, not clock speed.

Correct, I know what video you're talking about and IIRC the scaling shown there suggests that if Ryzen 3000 wants to beat Intel just with higher clock speeds it would need about 7ghz to do so - the conclusion is that gaming performance doesn't scale well on ryzen 3000 with higher clocks, there are other bottlenecks in the architecture that are too great, such as the memory latency

 

[SupraWez]

That would explain why single CCX models appear to be better for gaming.

Where else is the latency, the CCX to IO, I guess the affinity fabric.

I wonder then, on one of these new XT models disable CCX so only one is active and ramp the IF up keeping the ratio to 1:2 with memory, would be interesting as a test to see what difference it makes, obviously completely pointless for 90% of tasks where performance is way more than needed

 

[MrPils]

As mentioned earlier in this thread somewhere by another member, would like to see how high a 3900XT or 3800XT can be OC`ed with SMT disabled, wonder if it makes a difference.

Tell you tomorrow, my 3900XT shipped this morning

 

[CAT-THE-FIFTH]

I really don't so forget your issue. The only issue I have tbh is people being discourteous on this forum to vent whatever is going on in their everyday lives. I'll always buy AMD given a choice at equivalent performance I just want them to deliver what they say and if they don't I'll call them out. I also have a problem with people being rude to me for no good reason and when I refute their argument point by point seeing them disappearing as if it never happened, only to re-surface later with unnecessary jibes especially against legitimate opinions backed up with empirical data. I can see you also prefer data to personal sniping and if you look at my posts on this forum you'll see I've been an exemplar of civility and politeness. If others choose not to behave like this especially towards me (of which there are vanishingly few) then I won't accord them the civility I always extend to others the second or third time around.

She's actually done a fabulous job, I was just venting.

It's OK - I vented a lot about their B450/Zen3 moves,but ATM I think AMD is more deserving of my money than Intel. However,as I said if both companies start trying to take the mickey,I will just upgrade less often. I think the important thing is to wait until the price/performance is in your own personal ballpark,if you can hold off upgrading. Too many of these companies rely on people not having any self control,so try and exploit this.

Clock speed is not what is holding back gaming performance on ryzen.

I remember watching a video where they managed to overclock a ryzen 3000 chip to 5ghz to run some gaming benchmarks and it barely showed much improvement in framerates.

They concluded it was latency that holds back the performance the most, not clock speed.

I was saying this for years,as you could see Zen based CPUs underperforming in latency sensitive games. So when they fixed other sources of latency,ie,the caches,certain games improved a decent amount. The three main forms of latency Zen3 will need to tackle are memory-CCX latency,chiplet to chiplet latency,and inter-CCX latency.

The 8 core SKUs have a single chiplet so lack the chiplet to chiplet latency. However the huge L3 cache probably makes up for some aspects of the latency.

But when the Zen2 based APUs are released,they will be one SOC with reduced memory-CCX latency and no chiplet to chiplet latency. It will be interesting to see how these perform even with the lower amount of L3 cache.

 

[Jamin280672]

That would explain why single CCX models appear to be better for gaming.

Where else is the latency, the CCX to IO, I guess the affinity fabric.

I wonder then, on one of these new XT models disable CCX so only one is active and ramp the IF up keeping the ratio to 1:2 with memory, would be interesting as a test to see what difference it makes, obviously completely pointless for 90% of tasks where performance is way more than needed

I'll tell you later, my 3800xt is arriving today, and fabric needs to be run 1:1, 2:1 is punishing on latency, but I already know my ram will do 4000mhz, so if the infinity fabric does 2000mhz then I should be laughing.

 

[SupraWez]

Tell you tomorrow, my 3900XT shipped this morning

I'll tell you later, my 3800xt is arriving today, and fabric needs to be run 1:1, 2:1 is punishing on latency, but I already know my ram will do 4000mhz, so if the infinity fabric does 2000mhz then I should be laughing.

Thanks, looking forward to this testing

 

[jigger]

4.6 on 8 Zen 2 cores (3800XT) is pretty beastly for a price premium admittedly.

That would be a substantial drop in upgrade to my desktop system.

 

[Boot_Loop]

It makes a negligible difference over the 3800x in real terms.

Yeah but what about epeen?

Seriously though, adding 100-200mhz on top of single core boost is enough for Intel to call Comet Lake a whole new gen and that makes negligible perf difference so here we are. Some people like the numbers. Seeing 4599Mhz on CPU-Z with one of these would make me twitch a little down the nether region if nothing else.

 

[Jamin280672]

I plan to manually overclock it, id love it if it did 4.6ghz across all cores and 2000mhz IF, I did have a 3900X, but to be honest I wasnt utilizing it so I sold it, it was a rubbish chip anyway, I was going to buy the 3800X and thought may as well just wait for the 3800XT.

 

[Richdog]

Yeah but what about epeen?

Seriously though, adding 100-200mhz on top of single core boost is enough for Intel to call Comet Lake a whole new gen and that makes negligible perf difference so here we are. Some people like the numbers. Seeing 4599Mhz on CPU-Z with one of these would make me twitch a little down the nether region if nothing else.

Sure, if that's your thing. *shrugs*

 

[SupraWez]

I plan to manually overclock it, id love it if it did 4.6ghz across all cores and 2000mhz IF, I did have a 3900X, but to be honest I wasnt utilizing it so I sold it, it was a rubbish chip anyway, I was going to buy the 3800X and thought may as well just wait for the 3800XT.

I am looking to drop in a replacement for my 1700 which is manually overclocked to 3.8-3.9 ish, so looking at IPC improvements and 600-700 Mhz jump

YES PLEASE

 

[Jamin280672]

I am looking to drop in a replacement for my 1700 which is manually overclocked to 3.8-3.9 ish, so looking at IPC improvements and 600-700 Mhz jump

YES PLEASE

Well its in, went straight to 4.6ghz, tweaked the bios here and there, enabled XMP for my RAM, passed both Cinebench easily so ran 50 passes of IBT AVX, which it passed, 1.35v set in the bios, under load its drooping to 1.33v, any lower and it crashes to a black screen then reboot, going to play with the fabric now.

Seems very snappy, my boot is quicker than with my 3900X, but then that does only boost to 4.6ghz when it feels like it and only for short bursts.

 

[SupraWez]

Very interesting indeed

 

[hyperseven]

So the 3600XT is the best of the bunch of these respins over their X counterparts.

Ah well, will hold off until Zen3.

 

[jigger]

So the 3600XT is the best of the bunch of these respins over their X counterparts.

Ah well, will hold off until Zen3.

Seems like the 3800XT.

 

[Boot_Loop]

So the 3600XT is the best of the bunch of these respins over their X counterparts.

Ah well, will hold off until Zen3.

I might put that on just before bed tonight to send me off. Lol he's alright and content is interesting but very monotonous.

I think it depends on the sample these reviewers get, Aussies HU seemed to get a crap 3600XT by comparison.

 

[Grim5]

Well its in, went straight to 4.6ghz, tweaked the bios here and there, enabled XMP for my RAM, passed both Cinebench easily so ran 50 passes of IBT AVX, which it passed, 1.35v set in the bios, under load its drooping to 1.33v, any lower and it crashes to a black screen then reboot, going to play with the fabric now.

Seems very snappy, my boot is quicker than with my 3900X, but then that does only boost to 4.6ghz when it feels like it and only for short bursts.

IF/FCLK overclocking yet? Try for 2000mhz

 

[Joxeon]

will hold off until Zen3.

Thats the smart option as the 4000 series will likely wipe the floor with the refreshes when they're released in a couple of months.

 

[Jamin280672]

IF/FCLK overclocking yet? Try for 2000mhz

Testing still, 4.6ghz, IF wouldnt go any further than 1900mhz, but ram is at 3800mhz 16-18-16-36-GDM 1.41v, will post some benchmarks soon, just making sure its stable, its quick thats for sure, said in an earlier post, I was going to buy a 3800X anyway so thought I may as well try the XT version instead.

I'll still buy a Ryzen 4000, will probably just give this one to my Dad.

I'll edit this post with benchmarks as I go along, that will do for memtest: https://imgur.com/0BlWqD1

CPU-Z Benchmark very interesting validation: https://valid.x86.fr/lv8c7h

Cinebench R20 Single & Multi: https://imgur.com/OQYDnPo

Bear in mind im still tweaking the ram a little.

Dram Calc default test: https://imgur.com/HSOTjEl

 

[Pannalicour]

It's OK - I vented a lot about their B450/Zen3 moves,but ATM I think AMD is more deserving of my money than Intel. However,as I said if both companies start trying to take the mickey,I will just upgrade less often. I think the important thing is to wait until the price/performance is in your own personal ballpark,if you can hold off upgrading. Too many of these companies rely on people not having any self control,so try and exploit this.



I was saying this for years,as you could see Zen based CPUs underperforming in latency sensitive games. So when they fixed other sources of latency,ie,the caches,certain games improved a decent amount. The three main forms of latency Zen3 will need to tackle are memory-CCX latency,chiplet to chiplet latency,and inter-CCX latency.

The 8 core SKUs have a single chiplet so lack the chiplet to chiplet latency. However the huge L3 cache probably makes up for some aspects of the latency.

But when the Zen2 based APUs are released,they will be one SOC with reduced memory-CCX latency and no chiplet to chiplet latency. It will be interesting to see how these perform even with the lower amount of L3 cache.

This latency in games is ********. At his point its all about how a game is optimised. Look at far cry 5: 30 fps more on intel side in comparison with amd. Thats rediculious. These games are horrible written. Look at other games where amd is doing great. The better question is, how come one game is more latency sensitive than the other?

Btw I didn't do research on this one. Isn't so that zen+ has better latency than zen 2? How come zen 2 is performing better than?

I really think its comes down to how wel the game engine is written.