CPU Tests: Synthetic

Most of the people in our industry have a love/hate relationship when it comes to synthetic tests. On the one hand, they’re often good for quick summaries of performance and are easy to use, but most of the time the tests aren’t related to any real software. Synthetic tests are often very good at burrowing down to a specific set of instructions and maximizing the performance out of those. Due to requests from a number of our readers, we have the following synthetic tests.

Linux OpenSSL Speed: SHA256

One of our readers reached out in early 2020 and stated that he was interested in looking at OpenSSL hashing rates in Linux. Luckily OpenSSL in Linux has a function called ‘speed’ that allows the user to determine how fast the system is for any given hashing algorithm, as well as signing and verifying messages.

OpenSSL offers a lot of algorithms to choose from, and based on a quick Twitter poll, we narrowed it down to the following:

  1. rsa2048 sign and rsa2048 verify
  2. sha256 at 8K block size
  3. md5 at 8K block size

For each of these tests, we run them in single thread and multithreaded mode. All the graphs are in our benchmark database, Bench, and we use the sha256 results in published reviews.

(8-3c) Linux OpenSSL Speed sha256 8K Block (1T)(8-4c) Linux OpenSSL Speed sha256 8K Block (nT)

AMD has had a sha256 accelerator in its processors for many years, whereas Intel only enabled SHA acceleration in Rocket Lake. That's why we see RKL matching TR in 1T mode, but when the cores get fired up, TR and TR Pro streak ahead with the available performance and memory bandwidth. This is all about threads here, and 128 threads really matters.

GeekBench 5: Link

As a common tool for cross-platform testing between mobile, PC, and Mac, GeekBench is an ultimate exercise in synthetic testing across a range of algorithms looking for peak throughput. Tests include encryption, compression, fast Fourier transform, memory operations, n-body physics, matrix operations, histogram manipulation, and HTML parsing.

I’m including this test due to popular demand, although the results do come across as overly synthetic.

(8-1c) Geekbench 5 Single Thread(8-1d) Geekbench 5 Multi-Thread

DRAM Bandwidth

As we're moving from 2 channel memory on Ryzen to 4 channel memory on Threadripper then 8 channel memory on Threadripper Pro, these all have associated theoretical bandwidth maximums but there is a case for testing to see if those maximums can be reached. In this test, we do a simple memory write for peak bandwidth.

For 2-channel DDR4-3200, the theoretical maximum is 51.2 GB/s.
For 4-channel DDR4-3200, the theoretical maximum is 102.4 GB/s.
For 8-channel DDR4-3200, the theoretical maximum is 204.8 GB/s.

(8-2b) AIDA DRAM Write Speed

Here we see all the 4-channel Threadripper processors getting around 83 GB/s, but the Threadripper Pro can only achieve closer to its maximums when there are more cores present. Along with the memory controller bandwidth, AMD has to manage internal infinity fabric bandwidth and power to get the most out of the system. The fact that the 64C/64T achieves better than the 64C/128T might suggest that in 128T there is some congestion.

CPU Tests: Legacy and Web CPU Tests: SPEC
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  • mode_13h - Saturday, July 17, 2021 - link

    Sometimes they do show it. I wonder why not, this time?

    One thing to note is how some of the same applications they benchmark in standalone tests are *also* included in SPEC17. So, those tests can get over-represented.
  • Blastdoor - Wednesday, July 14, 2021 - link

    Re:

    "We are patiently waiting for AMD to launch Threadripper versions with Zen 3 – we hoped it would have been at Computex in June, but now we’re not sure exactly when."

    Maybe it will happen when Intel offers something remotely competitive in this market? Or maybe when supply constraints ease and AMD can fully meet demand?
  • mode_13h - Wednesday, July 14, 2021 - link

    Chagall (Threadripper 5000-series) is rumored to launch in August.
  • Threska - Wednesday, July 14, 2021 - link

    Long as AMD sticks to the same socket the platform should have longevity just like AM4.
  • Bernecky - Wednesday, July 14, 2021 - link

    Your "AMD Comparison" shows Threadripper DRAM as: 4×DDR4-3200.
    This is incorrect: I have a 3970X running on an ASUS ROG Zenith Extreme II Alpha, with
    256GB: 8×DDR4-3600(OC slightly).

    The Alpha no longer appears on the ASUS web site. Not sure what happened to it.
  • JMC2000 - Wednesday, July 14, 2021 - link

    The "4xDDR-3200" is referencing 4 channels @ a non-overclocked speed of 3200; what you have is 8 DDR4 DIMMs in 4 channels.
  • Railgun - Sunday, July 18, 2021 - link

    Still here on the UK site.

    https://www.asus.com/uk/Motherboards-Components/Mo...
  • Oxford Guy - Wednesday, July 14, 2021 - link

    ‘The only downside to EPYC is that it can only be used in single socket systems, and the peak memory support is halved (from 4 TB to 2 TB).’

    Eh?

    I assume you meant TR Pro. A big downside is that it’s Zen 2.
  • Thanny - Wednesday, July 14, 2021 - link

    Ryzen and Threadripper support ECC memory just fine. It's only registered memory that isn't supported, which is why you can only get 128GB into a Ryzen platform and 256GB into a Threadripper platform (32GB is the largest unbuffered DIMM you can get).

    The motherboard must also support it, which not all Ryzen motherboards do. But all Threadripper boards support ECC. I'm using 128GB of unbuffered ECC right now with a 3960X.
  • willis936 - Thursday, July 15, 2021 - link

    >Ryzen and Threadripper support ECC memory just fine

    A common misconception. Error reporting does not work with any AM4 chipset on non-pro AMD processors. Sure you have ECC, maybe. How do you know the soft error rate isn't massive?

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