2nd Gen Threadripper 2990WX review: AMD's 32-core CPU is insanely fast but not for everyone

AMD's Ryzen Threadripper 2990WX crushes multi-threaded tasks like we've never seen before.

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32-core Threadripper 2990WX gaming performance

We actually considered not running any gaming benchmarks on the 32-core Threadripper 2990WX, because if you bought this CPU to play Fortnite, you made a huge mistake. There are far better choices you can make with either Core i7 or Ryzen 7 over the Threadripper 2990WX. 

But you don’t care, so we ran them anyway. First up is Tom Clancy’s Rainbow Six Siege at a fairly low resolution (for a GTX 1080, anyway) of 1920x1080, and with a visual quality setting of Ultra. We ran the Threadripper 2990WX in both its default Creator mode and in the 1/4, legacy mode which switches off three of the four dies under the lid.

The result? With all of its cores hot the 2990WX is a yawner in performance, as it takes a hefty hit over the Core i9-7980XE CPU. But in legacy mode, it’s actually pretty close. And at more than 200 fps, it’s close enough not to matter at all.

ryzen threadripper 2990wx rainbow six siege 19x10 ultra dx12 IDG

While you shouldn’t buy an $1,800 32-core CPU to play games, it does rather well in legacy mode.

We also ran Rise of the Tomb Raider at 19x10 in DirectX 12 mode and legacy mode. The latter makes the Ryzen Threadripper 2990WX pretty dead-even with the Core i9 CPU. The message is, you still shouldn’t buy this class of CPU if you’re going to play games 75 percent of the time. If, however, you push pixels 75 percent of the time, it’s a no-brainer to buy the new Threadripper.

ryzen threadripper 2990wx rise of the tomb raider 19x10 very high dx12 IDG

When all 32 cores are hot, the Threadripper 2990WX can’t keep up with the smaller 18-core Core i9 in Rise of the Tomb Raider at 1920x1080. Switching to legacy mode evens the competition.

About that memory latency

We do honestly wonder how much of the Threadripper 2990WX’s performance is impacted when a die has to take a detour through another die. We tried to coax it out using AIDA 64’s memory latency test. We first ran it on default with all four dies on, then with two dies on, and finally with only one die on. We hoped that AIDA 64 would access memory from one of the compute-only dies and we’d see memory latency increase, but all three results were essentially the same. At this point, we’ll say it’s inconclusive but we’ll keep looking. Maybe it’s just not worth worrying about.

ryzen threadripper 2990wx aida 64 memory latency IDG

Because two of the four CPU dies on Ryzen Threadripper 2990WX lack memory controllers, we expect to see a slight increase in latency in theory, but we had no luck measuring it.

Thermals and boost performance

The top-end 32-core Threadripper 2990WX has a rated Thermal Design Power (TDP) of 250 watts, which is the maximum heat it will dissipate before hitting a wall. The 2990WX also has a total socket power of 250 watts, which it'll hit a few milliseconds after doing any heavy multi-threaded loads. What this means is that you need to keep the CPU well fed with power and generally pretty cool.

Overall, we saw temperatures in the range of about 113 degrees Fahrenheit (45 degrees Celsius) during much of our testing on our Enermax Liqtech TR4 cooler, so it doesn’t require anything too exotic. We actually saw similar performance with the optional  $99 “stock” Wraith Ripper heat sink.

We also want to point out that it was very easy to push the Threadripper 2990WX out of its top boost speeds. Applications that normally would not bump CPUs out of boost speeds, such as Valve’s Steam, would do it to Threadripper. For example, with Steam installed, minimized and essentially doing nothing, the highest boost clock we saw was 3.4GHz to 3.5GHz. Once we exited Steam, we saw saw boost clocks of 3.9GHz to 4GHz. Fortunately, Steam was only installed and running for our gaming tests.

In fact, even using the Ryzen Master software to monitor Threadripper was enough to kick the CPU out of its top boost speeds limiting it to 3.5GHz rather than 4.1GHz. AMD officials were able to replicate that experience, but the company said its own results with Steam weren't as bad as what we reported.

Ryzen Master IDG

The new Ryzen Master utility gives you a glimpse of the cores in the crazy 32-core Ryzen Threadripper. Stars mean better CPU cores and the circles mean the next best CPU Core. We did run in to an issue where the CPU not boost when running the utility though.

32-core Threadripper Performance analysis

Take today’s multi-core CPUs, which all react differently to thermals and power loads, and throw them software that varies in thread parallelization efficiency and you basically get a big question mark on what to expect in performance. 

To give you a general idea of what to expect, we take Cinebench R15 and run it repeatedly while increasing the threads from 1 to 64. While Cinebench isn’t going to tell you quite the same thing as a single-threaded game or Photoshop or an application that may effectively use 8 threads, it can tell us in general what you can expect out of a CPU under certain light or heavy loads.

For comparison, we took the 32-core Threadripper 2990WX and compared it to the 18-core Core i9-7980XE. The result: On the left side of the chart, the higher boost clocks and slightly better efficiency of the cores in the Core i9 give it a significant edge in performance. In fact, the Core i9 actually has a hefty performance advantage all the way up until you get to 28 threads, or the equivalent of a 14-core CPU.

18 ryzen threadripper 2990wx cinebench thread scaling IDG

We used Cinebench R15 to measure sequential performance from 1 to 64 threads to gauge performance in multi-threaded applications. The 32-core Ryzen Threadripper 2990WX just crushes the 18-core Core i9-7980X at the top end, but it can’t hang with the Intel CPU on lighter loads.

Threadripper 2990WX wins the heavy loads

As expected, once you start to climb above 28 threads, the sheer number of cores and threads in the 2990WX outgun the Core i9. Because the chart above doesn’t give you a sense of just how much of an advantage each has over the other, we generated a chart based on the percent. As you can see, the Core i9 offers up to 20 percent more performance on those “light” loads of up to 28 threads. Move to the right though, and the Threadripper 2990WX can exceed the performance of the Core i9 by 50 to nearly 60 percent.

ryzen threadripper 2990wx cinebench thread scaling percentage IDG

To give you an idea of how the previous Cinebench chart translates, we calculated the difference as a percentage. You can see the Core i9 has a big advantage on lighter loads, but the Threadripper crushes it on heavy loads.

What should you buy?

Frankly, if you tend to have workloads that aren’t going to scale and you don’t intend to multi-task heavily, the higher performance of the Core i9-7980XE might actually make more pragmatic sense. But if you do high-performance, heavily multi-threaded loads or multi-task heavily—you can’t look at the performance of the 32-core Threadripper and walk away.

The money shot

The literal money shot is just how much value you’re getting out of the Threadripper platform. It’s crazy to think that an $1,800 CPU can be a good value, but it truly is if you consider how much you’re paying per thread. AMD has amazingly introduced a new CPU with more cores than consumers have ever seen, and it has lowered the price at the same time. If that isn’t a deal, we don’t know what is.

21 bucks per thread IDG

When you look at how much you’re paying per thread for a CPU, AMD’s the big winner. Perhaps worse, how does Intel sell a consumer 28-core CPU at a competing price, when the server version is almost $9,000?

Conclusion

First let’s make it crystal-clear: The 32-core Threadripper 2990WX ($1799 on Newegg or Amazon) is not the CPU for most of us. Not by a long shot. For those of us who play games, edit some photos, browse the web and even do occasional video editing, an 8-core CPU is plenty, while a 16-core CPU is overkill. A 32-core CPU is double-overkill and honestly a waste. A Ryzen 7 or Core i7 is the more sound investment.

But for those of us who actually do push pixels around for a living, this new 32-core Ryzen Threadripper is Thor’s hammer falling right into your hands with a crackle of  lightning and thunder. For these heavy-hitters, it's well worth the price.

Correction: Our bucks per thread chart used outdated pricing information for older AMD CPUs. PCWorld regrets the error.

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