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Poll: Ryzen 7950X3D, 7900X3D, 7800X3D
- Thread starter kindai
- Start date
Caporegime
Apply EXPO, test. If everything's good, try 2200 FCLK in BIOS with EXPO. Indications of unstable FCLK would be random restarts, drops in MB performance when doing 20+ consecutive back to back runs of Linpack 1.1.5 Xtreme (pick 10GB option) , or cracking sound when listening to videos. If you get issues, try 2167. Rinse repeat until you find the right one. Higher FCLK should = lower latency in Aida64 too, so if you increase FCLK and latency stays the same or increases, dial back.
If everything's good after that, you can move on to curve optimiser as suggested above.
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Caporegime
ignore wrong thread 
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I'm thinking of going back to full gaming PC and looking at a few specs - I know the 7800X3D is the recommended, but considering there are some extremely good deals (for cheaper) on the 7900X3D... would I be making a huge mistake if I were to go that route? I've always been AIO on my last couple Ryzen chips (most recently the 5950X), but thinking of Air cooling this time around.
Man of Honour
From the reading up I did when deciding which to buy the 7900x3d is the worst choice of the three due to it only have 6 cores per CCD. If you really wanted extra cores for say 50/50 productivity/gaming the 7950x3d would be better otherwise the 7800x3d is the best choice for gaming.
For air cooling you need not spend any more than the £35 or so for the Thermalright Phantom Spirit PS120. I have a Thermalright Peerless Assassin on mine and yesterday while stress testing after playing with PBO my temps remained under 60 degrees C. No doubt it will be a tad warmer today because it's hotter here today but the PS120 would be my recommendation. It's similar to the Peerless Assassin but has a extra heatpipe and cools a little better. If you want extra bling then the Thermalright Phantom Spirit PS120 Evo is a excellent choice. There is no need to pay Noctua prices when you can have a similar performance for a fraction of the cost.
For air cooling you need not spend any more than the £35 or so for the Thermalright Phantom Spirit PS120. I have a Thermalright Peerless Assassin on mine and yesterday while stress testing after playing with PBO my temps remained under 60 degrees C. No doubt it will be a tad warmer today because it's hotter here today but the PS120 would be my recommendation. It's similar to the Peerless Assassin but has a extra heatpipe and cools a little better. If you want extra bling then the Thermalright Phantom Spirit PS120 Evo is a excellent choice. There is no need to pay Noctua prices when you can have a similar performance for a fraction of the cost.
Soldato
This is correct. Dual CCD adds latency and negatively affects gaming performance.
A CCD is basically a single chip with a number of cores and the CPU uses a communication bus between each CCD to allocate processing between the cores (known as infinity fabric).
Intel criticised AMD for this calling their CPUs “glued together” but then went and did the same thing when they realised how hard it is to make one CCD with more than 8 cores.
With the 7950X3D, it has dual CCD but that’s 8 cores per CCD and you can just tell the OS to only use the cores in CCD one or two which improves performance.
You can use either AMDs own software or a utility to force a game to only use a select number of cores (the name of which escapes me).
Thanks - will have a look at the 7800X3D/7950X3D, was only edging towards (knowing slightly less performance) the 7900X3D because of the price. Regarding cooling, had originally looked at getting the Thermalright Peerless Assassin 120 SE, but will consider the slightly cheaper Sprit too!
Good to know, thanks!
Personally not a fan of the 7900 it can be very strong for some tasks but fall down for others - which gets hidden sometimes in the average numbers of reviews and benchmarks. We are in a funny place right now where most games run fine on 6/12 or less but a few games starting to take advantage of 8/16.
I have a question... Had my 7950X3d a while now just using the gamebar method as normal. Nearly all the time it runs fine, but I've noticed in certain game, especially Frostbite engine games like Dragon age, Battlefield etc that it'll use the 8 cache cores but also spills over into 2 of the Frequency cores. Wouldn't that increase latency and affect performance?
Caporegime
Not necessarily, if the main threads are running on the cache CCD but maybe physics on the frequency CCD them you're probably getting the best of both worlds, idealy that is how you would want it to work, its only when the bits of the code that benefit from the cache CCD are running on the frequency CCD that it becomes a problem,
As for latency, that only becomes a problem when the same worlkload is moving between the CCD's, Windows likes to move work around between cores, that was always a problem for these multi-ccd CPU's because that work needs to pass through the memory controller when switching CCD's, that aspect of windows was fixed, or supposedly fixed for these CPU's years ago.
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Soldato
probably not if gaming is your main use. 7900 has 12 cores over 2 CCD so technically for gaming the 8 core over 1 CCD in the 7800x3d would be better, at least that's my takeaway from what I have been reading in this thread.
Associate
7800X3D is the way to go.
Caporegime
At clearance price it's not a terrible CPU, good multithreaded performance and solid gaming performance but it is a 6+6 design with only one 6 core CCD having 3D cache.
The issue will be longevity, if games start using 8 cores routinely then the 7900X might struggle as load will split across the 2 CCDs. Personally if mostly gaming I'd rather have the 7800X3D and just make a cup of tea whilst doing the odd encode.
Current pricing is pretty off putting.
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The performance loss isn't that big for the most part, but it is suboptimal for gaming. The extra 4 cores are very nice for anything decently multithreaded.
Caporegime
Just game bar.