If you’re interested in Linux performance, you may want to take a look at our experiences with the 3990X here.

In our look at AMD’s Ryzen Threadripper 3990X in Linux, we saw many occasions where the monstrous 64-core chip rose to the occasion, and delivered compelling scaling. It did quickly become clear, though, that much of the software industry hasn’t caught onto the idea of CPUs having so many threads. We can hope that AMD’s latest offering will encourage more developers to take many-core chips into greater consideration going forward.

Not all workloads require as many threads as the 3990X provides, and that’s important to acknowledge. In some cases, having so many threads could act as a detriment to performance in workloads that won’t scale so high. If you’re a gamer, this chip is almost certainly not for you. If you’re a workstation user whose workload can use as many threads as you can throw at it, then you will see a benefit.

You can’t mention “core counts” without hearing someone shout “rendering!”, so that’s of course a big focus of AMD’s for a chip like this. We remember at its EPYC 2 launch event last year, AMD had shown Blender rendering taking place on a dual-EPYC 256-thread machine, which highlighted the fact pretty well that it’s not only servers that can take good advantage of a huge number of threads.

For video encoding, scaling to such large CPUs has been challenging for a while, and not a great deal has improved since the release of the 2990WX in late 2018. As we’ll see in our Premiere Pro tests later, though, codec choices do make a difference. As for other workloads, we’ll be tackling those as well.

With its niche focus for the market’s biggest performance hounds, it should come as no surprise that the Threadripper 3990X carries a price-premium versus the other Threadrippers, coming in at $3,990 USD. Expensive, yes, but not when compared to the Intel competition. It was only a few years ago when Intel charged nearly $2K for an 18-core – and today we have a 64-core for $4K.

Despite being such a bleeding-edge processor, there’s nothing special a user needs to do for the 3990X that they wouldn’t have to do for the 3960X or 3970X. The officially max supported DRAM speed is 3200MHz for 128GB of memory if four DIMMs are used, and 2666MHz if eight are. We tested 64GB at 3600MHz, so the answer is “yes, you can go higher”. Of course, your mileage will vary.

Here’s AMD’s current Ryzen lineup for reference:

AMD’s Ryzen & Ryzen Threadripper Lineup Cores Clock (Turbo) L2+L3 Memory TDP Price Ryzen Threadripper 3990X 64 (128T) 2.9 GHz (4.3) 288MB Quad 280W $3990 3970X 32 (64T) 3.7 GHz (4.5) 144MB Quad 280W $1999 3960X 24 (48T) 3.8 GHz (4.5) 140MB Quad 280W $1399 Ryzen 9 R9 3950X 16 (32T) 3.5 GHz (4.7) 72MB Dual 105W $749 R9 3900X 12 (24T) 3.8 GHz (4.6) 70MB Dual 105W $499 Ryzen 7 R7 3800X 8 (16T) 3.9 GHz (4.5) 36MB Dual 95W $399 R7 3700X 8 (16T) 3.6 GHz (4.4) 36MB Dual 65W $329 Ryzen 5 R5 3600X 6 (12T) 3.8 GHz (4.4) 35MB Dual 95W $249 R5 3600 6 (12T) 3.6 GHz (4.2) 35MB Dual 65W $199 Ryzen w/ Radeon Vega Graphics R5 3400G 4 (8T) 3.7 GHz (4.2) 0.5+4MB Dual 65W $149 R3 3200G 4 (4T) 3.6 GHz (4.0) 0.5+4MB Dual 65W $99

Although we tested the 3990X with just 64GB of memory, AMD suggests that 128GB should be considered a minimum, and for the biggest workloads, 256GB is even better. Naturally, you will have to scale your configuration according to your needs, but if you are buying a CPU like the 3990X, then it’s safe to say that 128GB+ should be the target.

Thanks to the fact that the Zen 2 architecture is a lot more accommodating to high-frequency memory than the original Zen, you may want to consider going for a DDR4-3600 kit, as long as it’s been validated to work in this platform. The safe choice is 3200, since that’s officially supported – but remember, four sticks are better than eight.

We often receive reference performance numbers when we tackle a new CPU for review, and in the case of the 3990X, we haven’t quite been able to match what AMD has shown. Even after swapping motherboards, we haven’t been able to catch up to AMD, but as always, we’ll continue to test after-the-fact, and see what improves as software or firmware updates come out. It’s worth noting that we sanity checked with a few reviewer friends, and none of them are experiencing the same under-performing results as us. For now, we shall blame gremlins.



A fun, but unstable 3.6GHz all-core 3990X overclock

Because we ended up spending so much time tweaking our system to try to catch up to AMD’s reported numbers, we decided to spend some time overclocking, and were left surprised by the potential overall. We’re still exploring what’s stable, but we can say that you can easily gain a few hundred MHz to reach some impressive scores (+10% to Cinebench, for example). The shot above is of a 3.6GHz overclock, but to be clear, that was just to reach high scores. It is not at all stable for general operation.

On the next page, you can peruse our test systems and methodologies; or jump straight to the tests on page three.