Test Bed and Setup - Compiler Options

For the rest of our performance testing, we’re disclosing the details of the various test setups:

Intel - Dual Xeon Platinum 8380

For our new Ice Lake test system based on the Whiskey Lake platform, we’re using Intel’s SDP (Software Development Platform 2SW3SIL4Q, featuring a 2-socket Intel server board (Coyote Pass).

The system is an airflow optimised 2U rack unit with otherwise little fanfare.

Our review setup solely includes the new Intel Xeon 8380 with 40 cores, 2.3GHz base clock, 3.0GHz all-core boost, and 3.4GHz peak single core boost. That’s unusual about this part as noted in the intro, it’s running at a default 205W TDP which is above what we’ve seen from previous generation non-specialised Intel SKUs.

CPU 2x Intel Xeon Platinum 8380 (2.3-3.4 GHz, 40c, 60MB L3, 270W)
RAM 512 GB (16x32 GB) SK Hynix DDR4-3200
Internal Disks Intel SSD P5510 7.68TB
Motherboard Intel Coyote Pass (Server System S2W3SIL4Q)
PSU 2x Platinum 2100W

The system came with several SSDs including Optane SSD P5800X’s, however we ran our test suite on the P5510 – not that we’re I/O affected in our current benchmarks anyhow.

As per Intel guidance, we’re using the latest BIOS available with the 270 release microcode update.

Intel - Dual Xeon Platinum 8280

For the older Cascade Lake Intel system we’re also using a test-bench setup with the same SSD and OS image as on the EPYC 7742 system.

Because the Xeons only have 6-channel memory, their maximum capacity is limited to 384GB of the same Micron memory, running at a default 2933MHz to remain in-spec with the processor’s capabilities.

CPU 2x Intel Xeon Platinum 8280  (2.7-4.0 GHz, 28c, 38.5MB L3, 205W)
RAM 384 GB (12x32 GB) Micron DDR4-3200 (Running at 2933MHz)
Internal Disks Crucial MX300 1TB
Motherboard ASRock EP2C621D12 WS
PSU EVGA 1600 T2 (1600W)

The Xeon system was similarly run on BIOS defaults on an ASRock EP2C621D12 WS with the latest firmware available.

AMD - Dual EPYC 7763 / 7713 / 75F3 / 7662

In terms of testing the new EPYC 7003 series CPUs, unfortunately due to our malfunctioning Daytona server, we weren’t able to get first-hand experience with the hardware. AMD graciously gave us remote access to one of their server clusters – we had full controls of the system in terms of BMC as well as BIOS settings.

CPU ​2x AMD EPYC 7763 (2.45-3.500 GHz, 64c, 256 MB L3, 280W) /
2x AMD EPYC 7713 (2.00-3.365 GHz, 64c, 256 MB L3, 225W) /
2x AMD EPYC 75F3 (3.20-4.000 GHz, 32c, 256 MB L3, 280W) /
2x AMD EPYC 7662 (2.00-3.300 GHz, 64c, 256 MB L3, 225W)
RAM 512 GB (16x32 GB) Micron DDR4-3200
Internal Disks Varying
Motherboard Daytona reference board: S5BQ
PSU PWS-1200

Software wise, we ran Ubuntu 20.10 images with the latest release 5.11 Linux kernel. Performance settings both on the OS as well on the BIOS were left to default settings, including such things as a regular Schedutil based frequency governor and the CPUs running performance determinism mode at their respective default TDPs unless otherwise indicated.

AMD - Dual EPYC 7742

Our local AMD EPYC 7742 system, due to the aforementioned issues with the Daytona hardware, is running on a SuperMicro H11DSI Rev 2.0.

CPU ​2x AMD EPYC 7742 (2.25-3.4 GHz, 64c, 256 MB L3, 225W)
RAM 512 GB (16x32 GB) Micron DDR4-3200
Internal Disks Crucial MX300 1TB
Motherboard SuperMicro H11DSI0
PSU EVGA 1600 T2 (1600W)

As an operating system we’re using Ubuntu 20.10 with no further optimisations. In terms of BIOS settings we’re using complete defaults, including retaining the default 225W TDP of the EPYC 7742’s, as well as leaving further CPU configurables to auto, except of NPS settings where it’s we explicitly state the configuration in the results.

The system has all relevant security mitigations activated against speculative store bypass and Spectre variants.

Ampere "Mount Jade" - Dual Altra Q80-33

The Ampere Altra system we’re using the provided Mount Jade server as configured by Ampere. The system features 2 Altra Q80-33 processors within the Mount Jade DVT motherboard from Ampere.

In terms of memory, we’re using the bundled 16 DIMMs of 32GB of Samsung DDR4-3200 for a total of 512GB, 256GB per socket.

CPU ​2x Ampere Altra Q80-33 (3.3 GHz, 80c, 32 MB L3, 250W)
RAM 512 GB (16x32 GB) Samsung DDR4-3200
Internal Disks Samsung MZ-QLB960NE 960GB
Samsung MZ-1LB960NE 960GB
Motherboard Mount Jade DVT Reference Motherboard
PSU 2000W (94%)

The system came preinstalled with CentOS 8 and we continued usage of that OS. It’s to be noted that the server is naturally Arm SBSA compatible and thus you can run any kind of Linux distribution on it.

The only other note to make of the system is that the OS is running with 64KB pages rather than the usual 4KB pages – this either can be seen as a testing discrepancy or an advantage on the part of the Arm system given that the next page size step for x86 systems is 2MB – which isn’t feasible for general use-case testing and something deployments would have to decide to explicitly enable.

The system has all relevant security mitigations activated, including SSBS (Speculative Store Bypass Safe) against Spectre variants.

The system has all relevant security mitigations activated against the various vulnerabilities.

Compiler Setup

For compiled tests, we’re using the release version of GCC 10.2. The toolchain was compiled from scratch on both the x86 systems as well as the Altra system. We’re using shared binaries with the system’s libc libraries.

Ice Lake Xeon Processor List and Competition Topology, Memory Subsystem & Latency
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  • Drazick - Wednesday, April 7, 2021 - link

    The ICC compiler has much better vectorization engine than the one in GCC. It will usually generate better vectorized code. Especially numerical code.

    But the real benefit of ICC is its companion libraries: VSML, MKL, IPP.
  • Oxford Guy - Wednesday, April 7, 2021 - link

    I remember that custom builds of Blender done with ICC scored better on Piledriver as well as on Intel hardware. So, even an architecture that was very different was faster with ICC.
  • mode_13h - Thursday, April 8, 2021 - link

    And when was this? Like 10 years ago? How do we know the point is still relevant?
  • Oxford Guy - Sunday, April 11, 2021 - link

    How do we know it isn't?

    Instead of whinge why not investigate the issue if you're actually interested?

    Bottom line is that, just before the time of Zen's release, I tested three builds of Blender done with ICC and all were faster on both Intel and Piledriver (a very different architecture from Haswell).

    I asked why the Blender team wasn't releasing its builds with ICC since performance was being left on the table but only heard vague suggestions about code stability.
  • Wilco1 - Sunday, April 11, 2021 - link

    This thread has a similar comment about quality and support in ICC: https://twitter.com/andreif7/status/13808945639975...
  • KurtL - Wednesday, April 7, 2021 - link

    This is absolutely untrue. There is not much special about AOCC, it is just a AMD-packaged Clang/LLVM with few extras so it is not a SPEC compiler at all. Neither is it true for Intel. Sites that are concerned about getting the most performance out of their investments often use the Intel compilers. It is a very good compiler for any code with good potential for vectorization, and I have seen it do miracles on badly written code that no version of GCC could do.
  • Wilco1 - Wednesday, April 7, 2021 - link

    And those closed-source "extras" in AOCC magically improve the SPEC score compared to standard LLVM. How is it not a SPEC compiler just like ICC has been for decades?
  • JoeDuarte - Wednesday, April 7, 2021 - link

    It's strange to tell people who use the Intel compiler that it's not used much in the real world, as though that carries some substantive point.

    The Intel compiler has always been better than gcc in terms of the performance of compiled code. You asserted that that is no longer true, but I'm not clear on what evidence you're basing that on. ICC is moving to clang and LLVM, so we'll see what happens there. clang and gcc appear to be a wash at this point.

    It's true that lots of open source Linux-world projects use gcc, but I wouldn't know the percentage. Those projects tend to be lazy or untrained when it comes to optimization. They hardly use any compiler flags relevant to performance, like those stipulating modern CPU baselines, or link time optimization / whole program optimization. Nor do they exploit SIMD and vectorization much, or PGO, or parallelization. So they leave a lot of performance on the table. More rigorous environments like HPC or just performance-aware teams are more likely to use ICC or at least lots of good flags and testing.

    And yes, I would definitely support using optimized assembly in benchmarks, especially if it surfaced significant differences in CPU performance. And probably, if the workload was realistic or broadly applicable. Anything that's going to execute thousands, millions, or billions of times is worth optimizing. Inner loops are a common focus, so I don't know what you're objecting to there. Benchmarks should be about realizable optimal performance, and optimization in general should be a much bigger priority for serious software developers – today's software and OSes are absurdly slow, and in many cases desktop applications are slower in user-time than their late 1980s counterparts. Servers are also far too slow to do simple things like parse an HTTP request header.
  • pSupaNova - Wednesday, April 7, 2021 - link

    "today's software and OSes are absurdly slow, and in many cases desktop applications are slower in user-time than their late 1980s counterparts." a late 1980's desktop could not even play a video let alone edit one, your average mid range smartphone is much more capable. My four year old can do basic computing with just her voice. People like you forget how far software and hardware has come.
  • GeoffreyA - Wednesday, April 7, 2021 - link

    Sure, computers and devices are far more capable these days, from a hardware point of view, but applications, relying too much on GUI frameworks and modern languages, are more sluggish today than, say, a bare Win32 application of yore.

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