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It looks like there is generally a 18% - 40% performance hit with meltdown[1]: > On Linux distributions like Ubuntu 18.10 and Clear Linux the mitigation costs

It looks like there is generally a 18% - 40% performance hit with meltdown[1]: > On Linux distributions like Ubuntu 18.10 and Clear Linux the mitigation costs were about ~18% while both RHEL 8 Beta and openSUSE 15.0 had a nearly 40% hit. If we look at MDS mitigation for older MACs[2], it could be 40%: > Intel MDS Vulnerabilities Affecting 7th Gen And Below May Slow Macs By Up To 40%, Apple Warns If we look at MDS mitigation generally (if Intel is to be believed) we are looking at ~10% for most use cases[3] > Intel's benchmarks show a 6-14 percent drop in storage performance on a couple of Xeon processors, both with Hyper Threading enabled. Assuming that Intel is not showing a worst case scenario in any of these benchmarks, the hit to storage could be even bigger. > It's in workstations and data centers that mitigations are likely to have the biggest performance impact, depending on the workload. In a separate graph, for example, Intel shows a 19 percent drop in "server side Java" performance after disabling Hyper Threading on a Xeon Platinum 8180 processor (compared to having it turned on). In other words... total I have no idea what we'll be seeing. However, if we don't look at just "raw performance" in benchmarks when buying CPUs, AMD is likely a better purchase for most use cases at this point. [1] https://www.phoronix.com/scan.php?page=article&item=spec-melt-8way&num=2 https://www.phoronix.com/scan.php?page=article&item=spec-mel... [2] https://wccftech.com/intel-mds-vulnerabilities-affecting-7th-gen-and-below-may-slow-macs-by-up-to-40-apple-warns/ https://wccftech.com/intel-mds-vulnerabilities-affecting-7th... [3] https://www.pcgamer.com/intel-posts-benchmarks-showing-performance-impact-of-new-cpu-flaws/ https://www.pcgamer.com/intel-posts-benchmarks-showing-perfo...

the8472 7y ago
Phoronix just released new benchmarks covering MDS mitigations and the combined costs of all mitigations . https://www.phoronix.com/scan.php?page=article&item=mds-zombieload-mit&num=1 https://www.phoronix.com/scan.php?page=article&item=mds-zomb...
- nullwasamistake 7y ago
  For the lazy: "If looking at the geometric mean for the tests run today, the Intel systems all saw about 16% lower performance out-of-the-box now with these default mitigations and obviously even lower if disabling Hyper Threading for maximum security. The two AMD systems tested saw a 3% performance hit with the default mitigations. While there are minor differences between the systems to consider, the mitigation impact is enough to draw the Core i7 8700K much closer to the Ryzen 7 2700X and the Core i9 7980XE to the Threadripper 2990WX." Not looking good for Intel at the moment. It should also be noted that there's believable rumors that the mitigations are not fully effective unless hyperthreading is disabled.
  - makomk 7y ago
    I don't think it's just rumours. Microsoft, Apple and Red Hat have said that full mitigation requires disabling hyperthreading. While Intel don't recommend doing so, their justification for this is that most people don't actually need process protection anyway. They also note that "it’s important to understand that doing so does not alone provide protection against MDS", which is true - you need to disable hyperthreading and apply additional performance-sapping mitigations which require both microcode updates and operating system support. The hyperthreading-based variants seem to be a lot more powerful than the ones fixed by the other mitigations though.
    - nullwasamistake 7y ago
      Wow that's bad. With the mitigations + HT off were looking at more than 40% performance penalty for the average benchmark based on their stats
- petschge 7y ago
  That article reports: If looking at the geometric mean for the tests run today, the Intel systems all saw about 16% lower performance out-of-the-box now with these default mitigations and obviously even lower if disabling Hyper Threading for maximum security. The two AMD systems tested saw a 3% performance hit with the default mitigations. While there are minor differences between the systems to consider, the mitigation impact is enough to draw the Core i7 8700K much closer to the Ryzen 7 2700X and the Core i9 7980XE to the Threadripper 2990WX. Rough prices I just googled: Core i7 8700K is $390, Ryzen 7 2700x is $290, Core i9 7980XE is $1800 and Threadripper 2990WX is $1600.
ungamed 7y ago
You got a citation for the ubuntu vs rhel, as I figured they used the same patchset.
ksec 7y ago
Which makes you wonder why hasn't any major tech enthusiast website redo their benchmarks again with both security patch and HT disabled against AMD. I also don't think disabling HT is an over reaction, as far as I can see Intel's HT implementation is fundamentally flawed. Right now there aren't any site putting those number with AMD's number next to them. May be it is too much work and they will wait for the new Ryzen arrives.

the8472 7y ago

Phoronix just released new benchmarks covering MDS mitigations and the combined costs of all mitigations . https://www.phoronix.com/scan.php?page=article&item=mds-zombieload-mit&num=1 https://www.phoronix.com/scan.php?page=article&item=mds-zomb...

nullwasamistake 7y ago
For the lazy: "If looking at the geometric mean for the tests run today, the Intel systems all saw about 16% lower performance out-of-the-box now with these default mitigations and obviously even lower if disabling Hyper Threading for maximum security. The two AMD systems tested saw a 3% performance hit with the default mitigations. While there are minor differences between the systems to consider, the mitigation impact is enough to draw the Core i7 8700K much closer to the Ryzen 7 2700X and the Core i9 7980XE to the Threadripper 2990WX." Not looking good for Intel at the moment. It should also be noted that there's believable rumors that the mitigations are not fully effective unless hyperthreading is disabled.
- makomk 7y ago
  I don't think it's just rumours. Microsoft, Apple and Red Hat have said that full mitigation requires disabling hyperthreading. While Intel don't recommend doing so, their justification for this is that most people don't actually need process protection anyway. They also note that "it’s important to understand that doing so does not alone provide protection against MDS", which is true - you need to disable hyperthreading and apply additional performance-sapping mitigations which require both microcode updates and operating system support. The hyperthreading-based variants seem to be a lot more powerful than the ones fixed by the other mitigations though.
  - nullwasamistake 7y ago
    Wow that's bad. With the mitigations + HT off were looking at more than 40% performance penalty for the average benchmark based on their stats
petschge 7y ago
That article reports: If looking at the geometric mean for the tests run today, the Intel systems all saw about 16% lower performance out-of-the-box now with these default mitigations and obviously even lower if disabling Hyper Threading for maximum security. The two AMD systems tested saw a 3% performance hit with the default mitigations. While there are minor differences between the systems to consider, the mitigation impact is enough to draw the Core i7 8700K much closer to the Ryzen 7 2700X and the Core i9 7980XE to the Threadripper 2990WX. Rough prices I just googled: Core i7 8700K is $390, Ryzen 7 2700x is $290, Core i9 7980XE is $1800 and Threadripper 2990WX is $1600.

ungamed 7y ago

You got a citation for the ubuntu vs rhel, as I figured they used the same patchset.

ksec 7y ago

Which makes you wonder why hasn't any major tech enthusiast website redo their benchmarks again with both security patch and HT disabled against AMD. I also don't think disabling HT is an over reaction, as far as I can see Intel's HT implementation is fundamentally flawed. Right now there aren't any site putting those number with AMD's number next to them. May be it is too much work and they will wait for the new Ryzen arrives.