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Out of curiosity, has anybody had anything in the AMD Ryzen instruction set missing that required you to purchase an Intel 9xxx instead? Any significant differ

Out of curiosity, has anybody had anything in the AMD Ryzen instruction set missing that required you to purchase an Intel 9xxx instead? Any significant differences in regards to scientific applications or machine learning?

mpfundstein 7y ago
Also interested in this
bcaa7f3a8bbc 7y ago
+1. I've heard some optimizations in scientific computing (e.g. Gaussian 16, from someone who does chemistry) is not available without AVX, but I'm not a practitioner of scientific computing, and know nothing about the current situation. Could anyone share your experience? Also, what is the performance figure of multimedia/encoding performance?
wmf 7y ago
The rr debugger had problems with Ryzen. AMD doesn't have AVX512 but that's more of a performance difference; code shouldn't be written to require it.
pella 7y ago
in ZEN2: "The key highlight improvement for floating point performance is full AVX2 support. AMD has increased the execution unit width from 128-bit to 256-bit, allowing for single-cycle AVX2 calculations, rather than cracking the calculation into two instructions and two cycles. This is enhanced by giving 256-bit loads and stores, so the FMA units can be continuously fed. AMD states that due to its energy aware scheduling, there is no predefined frequency drop when using AVX2 instructions (however frequency may be reduced dependent on temperature and voltage requirements, but that’s automatic regardless of instructions used)" "In the floating point unit, the queues accept up to four micro-ops per cycle from the dispatch unit which feed into a 160-entry physical register file. This moves into four execution units, which can be fed with 256b data in the load and store mechanism. Other tweaks have been made to the FMA units than beyond doubling the size – AMD states that they have increased raw performance in memory allocations, for repetitive physics calculations, and certain audio processing techniques. Another key update is decreasing the FP multiplication latency from 4 cycles to 3 cycles. That is quite a significant improvement. AMD has stated that it is keeping a lot of the detail under wraps, as it wants to present it at Hot Chips is August. We’ll be running a full instruction analysis for our reviews on July 7th." https://www.anandtech.com/print/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome https://www.anandtech.com/print/14525/amd-zen-2-microarchite... > Any significant differences in regards to scientific applications or machine learning? The PCIe4.0 is good for Data Science ( NVMe Disk / GPU machine learning ) "Corsair MP600 SSDs will offer up to 4950 MB/s sequential read speed as well as up to 4250 MB/s sequential write speed when used with a PCIe 4.0 x4 interface, which is substantially faster when compared to modern PCIe 3.0 x4 drives." https://www.anandtech.com/show/14584/corsair-mp600-pcie-4-ssd-available-for-preorder-2tb https://www.anandtech.com/show/14584/corsair-mp600-pcie-4-ss...
- nsporillo 7y ago
  Darn, I just bought a Samsung 970 Pro 1TB NVMe drive for my new Ryzen zen2 build. I probably should have waited to buy this PCI4.0 drive instead. Thanks for sharing
- driverdan 7y ago
  > Corsair MP600 SSDs will offer up to 4950 MB/s sequential read speed as well as up to 4250 MB/s sequential write speed when used with a PCIe 4.0 x4 interface WOW! Looks like they haven't announced pricing yet. I wonder what those drives will cost.
  - zamadatix 7y ago
    $250 for the 1 TB version and $450 for the 2 TB model, Corsai accidentally put the listings up early on Amazon a few days ago and then took them down
vbezhenar 7y ago
I'm considering Intel for my next workstation because I want to be able to run macOS at least in VirtualBox (or just run Hackintosh, did not decide yet). For some reason macOS does not like AMD CPUs.
- pella 7y ago
  > For some reason macOS does not like AMD CPUs. Reddit:"Mojave, now on Ryzen!" https://www.reddit.com/r/hackintosh/comments/a95xlo/mojave_now_on_ryzen/ https://www.reddit.com/r/hackintosh/comments/a95xlo/mojave_n...
  - vbezhenar 7y ago
    Installing custom built kernel on a proprietary OS sounds like a recipe for disaster. It's likely to break on the first update. More like a proof of concept rather than stable solution.
- TwoNineA 7y ago
  You can run MacOS through KVM easy on Ryzen. Even GPU passthrough works fine.
  - LeSaucy 7y ago
    iMessage and other features generally break when running amd macintoshes, intel ones are indistinguishable.
    - webmobdev 7y ago
      Why would they break if macOS itself runs fine on AMD? These softwares run on macOS and don't make any system calls directly by bypassing the OS, right?
      - mainlineman 7y ago
        They typically check for a network interface from a real Mac. Using a Hackintosh you can't spoof some of the NIC details that are detected and cause iCloud/iMessage to not work.
devttyeu 7y ago
The mozilla/rr debugger doesn't work on Ryzen CPUs - https://github.com/mozilla/rr/issues/2034 https://github.com/mozilla/rr/issues/2034 (rr stands for Record and Replay Framework, it's a gdb extension which allows for reverse execution)
- p_l 7y ago
  Interesting that GDB had its own "time travel" support for longer that afaik works on AMD. Will have to see what rr brings to the table.
  - unmole 7y ago
    GDB's recording is extremely limited. It doesn't even work on multi threaded programs.
    - roca 7y ago
      It's also about 1000x slowdown during recording, where rr is < 2x.
wil421 7y ago
Yes official and guaranteed support for ECC but it was an i3-8100 instead of an AMD equivalent. For a FreeNAS build. I will upgrade it to a Xeon E-21XX or whatever supports my Supermicro C246 motherboard in the future. AMD doesn’t test ECC on Ryzen but doesn’t turn it off. Server grade components are not as common either. Threadrippers are tempting but I like to play with EXSI and Intel’s virtualization is handy. My next desktop might be a Threadripper but my i7-7700K and Intel QSV is good enough for Plex and 4K. I would like have a 10gb backbone with SFP+ so I can play with Fiber, DAC, and 10gb Ethernet.
- AaronFriel 7y ago
  What precludes you from using ESXi and virtualization on AMD's platform? The virtualization extensions to x86 are common to both AMD and Intel. Even direct IO and IOMMU. Is there something missing?
  - p_l 7y ago
    The virtualization extensions are actually different, but yeah, VMware supports both across all platforms. I think it's only AMD Hackintosh where you might have an issue?
scott00 7y ago
I use the TSC for high precision timing, and turning TSC ticks into nanoseconds requires interpreting model specific registers, so my timing code would need AMD specific patches to work properly on those processors. Not necessarily a deal-breaker, but it would definitely be an annoyance for me if I did decide to switch. Probably not super relevant to scientific computing or ML though.
- TwoBit 7y ago
  How do you use the TSC for timing when the frequency is changing unpredictably?
  - wmf 7y ago
    Recent processors have invariant TSC.
miller_joe 7y ago
There might be meaningful differences in the hardware encode/decode for video. In the Plex community for example it seems like Intel CPUs are the best bet. They support a lot of codecs and can service multiple transcode streams. Consumer Nvidia GPUs are limited to 2. I don't think Plex supports hardware transcoding on AMD Ryzen or discrete GPUs at all right now. I haven't really looked into why yet, and could likely just be a software support issue in Plex. This, unfortunately, would be a deal breaker for my home-server use case, although I'm very happy AMD is finally competitive again, overall.
- toast0 7y ago
  The Zen2 chips being released and discussed here don't have a GPU. The Ryzen 3000 series APUs being released soon are using last year's Zen+ CPU architecture; and are only 4 cores, so not super comparable to a $2000 Intel CPU :)
colechristensen 7y ago
I have too frequently had problems with hardware support in OS outside Linux and Windows for non Intel chipsets. One that sticks out is virtualization support in freebsd and others. I don't know if it's still true but the time risk isn't worth the cost benefit for me any more.

mpfundstein 7y ago

Also interested in this

bcaa7f3a8bbc 7y ago

+1. I've heard some optimizations in scientific computing (e.g. Gaussian 16, from someone who does chemistry) is not available without AVX, but I'm not a practitioner of scientific computing, and know nothing about the current situation. Could anyone share your experience? Also, what is the performance figure of multimedia/encoding performance?

wmf 7y ago

The rr debugger had problems with Ryzen. AMD doesn't have AVX512 but that's more of a performance difference; code shouldn't be written to require it.

pella 7y ago

in ZEN2: "The key highlight improvement for floating point performance is full AVX2 support. AMD has increased the execution unit width from 128-bit to 256-bit, allowing for single-cycle AVX2 calculations, rather than cracking the calculation into two instructions and two cycles. This is enhanced by giving 256-bit loads and stores, so the FMA units can be continuously fed. AMD states that due to its energy aware scheduling, there is no predefined frequency drop when using AVX2 instructions (however frequency may be reduced dependent on temperature and voltage requirements, but that’s automatic regardless of instructions used)" "In the floating point unit, the queues accept up to four micro-ops per cycle from the dispatch unit which feed into a 160-entry physical register file. This moves into four execution units, which can be fed with 256b data in the load and store mechanism. Other tweaks have been made to the FMA units than beyond doubling the size – AMD states that they have increased raw performance in memory allocations, for repetitive physics calculations, and certain audio processing techniques. Another key update is decreasing the FP multiplication latency from 4 cycles to 3 cycles. That is quite a significant improvement. AMD has stated that it is keeping a lot of the detail under wraps, as it wants to present it at Hot Chips is August. We’ll be running a full instruction analysis for our reviews on July 7th." https://www.anandtech.com/print/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome https://www.anandtech.com/print/14525/amd-zen-2-microarchite... > Any significant differences in regards to scientific applications or machine learning? The PCIe4.0 is good for Data Science ( NVMe Disk / GPU machine learning ) "Corsair MP600 SSDs will offer up to 4950 MB/s sequential read speed as well as up to 4250 MB/s sequential write speed when used with a PCIe 4.0 x4 interface, which is substantially faster when compared to modern PCIe 3.0 x4 drives." https://www.anandtech.com/show/14584/corsair-mp600-pcie-4-ssd-available-for-preorder-2tb https://www.anandtech.com/show/14584/corsair-mp600-pcie-4-ss...

nsporillo 7y ago
Darn, I just bought a Samsung 970 Pro 1TB NVMe drive for my new Ryzen zen2 build. I probably should have waited to buy this PCI4.0 drive instead. Thanks for sharing
driverdan 7y ago
> Corsair MP600 SSDs will offer up to 4950 MB/s sequential read speed as well as up to 4250 MB/s sequential write speed when used with a PCIe 4.0 x4 interface WOW! Looks like they haven't announced pricing yet. I wonder what those drives will cost.
- zamadatix 7y ago
  $250 for the 1 TB version and $450 for the 2 TB model, Corsai accidentally put the listings up early on Amazon a few days ago and then took them down

vbezhenar 7y ago

I'm considering Intel for my next workstation because I want to be able to run macOS at least in VirtualBox (or just run Hackintosh, did not decide yet). For some reason macOS does not like AMD CPUs.

pella 7y ago
> For some reason macOS does not like AMD CPUs. Reddit:"Mojave, now on Ryzen!" https://www.reddit.com/r/hackintosh/comments/a95xlo/mojave_now_on_ryzen/ https://www.reddit.com/r/hackintosh/comments/a95xlo/mojave_n...
- vbezhenar 7y ago
  Installing custom built kernel on a proprietary OS sounds like a recipe for disaster. It's likely to break on the first update. More like a proof of concept rather than stable solution.
TwoNineA 7y ago
You can run MacOS through KVM easy on Ryzen. Even GPU passthrough works fine.
- LeSaucy 7y ago
  iMessage and other features generally break when running amd macintoshes, intel ones are indistinguishable.
  - webmobdev 7y ago
    Why would they break if macOS itself runs fine on AMD? These softwares run on macOS and don't make any system calls directly by bypassing the OS, right?
    - mainlineman 7y ago
      They typically check for a network interface from a real Mac. Using a Hackintosh you can't spoof some of the NIC details that are detected and cause iCloud/iMessage to not work.

devttyeu 7y ago

The mozilla/rr debugger doesn't work on Ryzen CPUs - https://github.com/mozilla/rr/issues/2034 https://github.com/mozilla/rr/issues/2034 (rr stands for Record and Replay Framework, it's a gdb extension which allows for reverse execution)

p_l 7y ago
Interesting that GDB had its own "time travel" support for longer that afaik works on AMD. Will have to see what rr brings to the table.
- unmole 7y ago
  GDB's recording is extremely limited. It doesn't even work on multi threaded programs.
  - roca 7y ago
    It's also about 1000x slowdown during recording, where rr is < 2x.

wil421 7y ago

Yes official and guaranteed support for ECC but it was an i3-8100 instead of an AMD equivalent. For a FreeNAS build. I will upgrade it to a Xeon E-21XX or whatever supports my Supermicro C246 motherboard in the future. AMD doesn’t test ECC on Ryzen but doesn’t turn it off. Server grade components are not as common either. Threadrippers are tempting but I like to play with EXSI and Intel’s virtualization is handy. My next desktop might be a Threadripper but my i7-7700K and Intel QSV is good enough for Plex and 4K. I would like have a 10gb backbone with SFP+ so I can play with Fiber, DAC, and 10gb Ethernet.

AaronFriel 7y ago
What precludes you from using ESXi and virtualization on AMD's platform? The virtualization extensions to x86 are common to both AMD and Intel. Even direct IO and IOMMU. Is there something missing?
- p_l 7y ago
  The virtualization extensions are actually different, but yeah, VMware supports both across all platforms. I think it's only AMD Hackintosh where you might have an issue?

scott00 7y ago

I use the TSC for high precision timing, and turning TSC ticks into nanoseconds requires interpreting model specific registers, so my timing code would need AMD specific patches to work properly on those processors. Not necessarily a deal-breaker, but it would definitely be an annoyance for me if I did decide to switch. Probably not super relevant to scientific computing or ML though.

TwoBit 7y ago
How do you use the TSC for timing when the frequency is changing unpredictably?
- wmf 7y ago
  Recent processors have invariant TSC.

miller_joe 7y ago

There might be meaningful differences in the hardware encode/decode for video. In the Plex community for example it seems like Intel CPUs are the best bet. They support a lot of codecs and can service multiple transcode streams. Consumer Nvidia GPUs are limited to 2. I don't think Plex supports hardware transcoding on AMD Ryzen or discrete GPUs at all right now. I haven't really looked into why yet, and could likely just be a software support issue in Plex. This, unfortunately, would be a deal breaker for my home-server use case, although I'm very happy AMD is finally competitive again, overall.

toast0 7y ago
The Zen2 chips being released and discussed here don't have a GPU. The Ryzen 3000 series APUs being released soon are using last year's Zen+ CPU architecture; and are only 4 cores, so not super comparable to a $2000 Intel CPU :)

colechristensen 7y ago

I have too frequently had problems with hardware support in OS outside Linux and Windows for non Intel chipsets. One that sticks out is virtualization support in freebsd and others. I don't know if it's still true but the time risk isn't worth the cost benefit for me any more.