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I have a rack with a few old Dell PowerEdge R710 with dual Intel Xeon X5650 processors (6 cores 12 threads per CPU). I use them to test the changes on my chess

by vinc 3y ago

I have a rack with a few old Dell PowerEdge R710 with dual Intel Xeon X5650 processors (6 cores 12 threads per CPU). I use them to test the changes on my chess engine in winter and they help keeping the house warm. They are very cheap. The slightly more recent Dell PowerEdge R720 can have CPUs with more cores and use a bit less electricity and noise but they are much more expensive where I live. I've been on the lookout for a more modern platform with more cores per $100 but couldn't find any yet.

adrian_b 3y ago
The best performance per dollar in a server for now is if it is built with desktop AMD Ryzen 7000 CPUs, e.g. Ryzen 9 7950X, whose performance per dollar is vastly better than that of any Intel Sapphire Rapids or AMD Genoa or Bergamo or Threadripper. (There are easily available AM5 motherboards with ECC support, and network cards up to those with dual 25 Gb/s ports in SFP connectors are also cheap.) Ryzen 7000 CPUs are not the best only when the performance of the CPU is less important than having a lot of PCIe lanes and/or memory concentrated in a single box, instead of being distributed in multiple boxes (for the latter case multiple Ryzen 7000 boxes are cheaper than a single big server with the same total amount of memory and total count of PCIe lanes). For a lot of memory and PCIe lanes in a single box, there are some Sapphire Rapids models with few cores that are quite cheap, but of course the Intel marketing has decided to cripple them by limiting their memory speed to DDR5-4400. The ubiquitous crippling of the cheap Intel SKUs is intended to force their customers to buy the SKUs with outrageous prices, but all that this has ever done to me was to force me to buy from their competition. For the same purpose, AMD Siena CPUs are expected to be competitive, but only if they will become available at retail, which is uncertain.
- alberth 3y ago
  I wish more web hosts offered Ryzen 7000s to lease. Hetzner, OVH and Contabo are some of the only few I’m aware of who does.
- zamadatix 3y ago
  Is it nefarious marketing or just that a lower end CPU with 8 memory channels doesn't need a whizzbang memory controller to get the memory capacity/performance it needs? Besides, doesn't the platinum version only go to 4800 MHz anyways? (split comment to separate topics)
  - adrian_b 3y ago
    Decreasing the DDR5 transfer rate from 4800 MHz to 4400 MHz may provide a minuscule improvement in Intel's CPU die yields, supposing that their manufacturing process is bad and it barely allows to reach the standard 4800 MHz frequency, which might be justified as allowing lower prices for the low-end SKUs. The users certainly do not want such a speed reduction, especially taking into account that they will usually buy standard DDR5-4800 modules, which will never be used at the performance that they have been paid for. It is very unlikely that the manufacturing cost reduction due to a relaxed specification for the memory controller is important. Cutting whatever features they could in the cheap SKUs, to annoy the customers (like disabling instruction subsets, and in Sapphire Rapids disabling the accelerators), has been the MO of Intel already for decades.
    - zamadatix 3y ago
      I'm not saying people directly want lower memory clocks rather I'm saying 4000/4400/4800 MHz doesn't seem to be a decision based on intentionally aiming to create upsell segmentation because 400 MHz of memory bandwidth on an 8 channel system is a completely irrelevant way to incentivize people while using lower quality binning and manufacturing to compete on price IS an incentive people in that range want, even if it comes at a minor cost in performance (that's the point of the low end SKUs!). E.g. Epyc segments memory performance in the Edge line by cutting the number of memory channels in HALF, the equivalent of dropping to 2400 MHz speed in a loaded server. Now there are other additional reasons that's actually attractive to buyers as well, namely the Edge class is expected to be lower power and driving 12 channels of high speed memory is counter to that goal, but it gives an idea of how miniscule 400 MHz of memory bandwidth is in terms of things that matter for low tier server performance. If anything I'd say that Epyc has support for 12 memory channels (win of the dedicated I/O die) is leaps and bounds more relevant. The Intel SKUs would need to run their 8 channels at 7200 MHz just to break even and here we are talking about 4400 MHz instead of 4800 MHz as a deciding reason to not buy an Intel server! Every manufacturer has the MO of artificially cutting features to segment things. Intel, AMD, Nvidia, Apple - all of them. Now maybe the folks at Intel marketing were smoking something funny that day and genuinely though this limitation would actually create incentive to go to a higher tier, who knows. Even then, why would that particular (poor) segmentation be a driver be worth choosing to exclude a brand over when the meaningful segments from all players are all much larger?
- zamadatix 3y ago
  You can get a 14900k with better performance (single core and multi core) for cheaper. Between my 7950X system and that I've found the Intel memory controller to handle higher RAM capacities speeds as well. It also comes with ECC support if you get the right motherboard and you get additional usable PCIe bandwidth over what the 7950X will expose.
  - nextos 3y ago
    Also Intel CPUs have much lower consumption while idling, right? As much as I like AMD, I find this a significant advantage for a workstation / small server.
    - adrian_b 3y ago
      It is true that the desktop Intel CPUs have lower idle consumption, usually by 10 to 15 W, than the desktop AMD CPUs. On the other hand, for any given performance at full load, the AMD CPUs have a much lower power consumption, as low as two thirds. Which is preferable depends on the application. For a personal computer, idle power consumption may be the most important. For a server, the power consumption when used is normally more important. I have several servers in my home, which are used intermittently. Their idle power consumption does not matter much, because whenever they are not used they are shut down. Wake-on-Ethernet is enabled on them, and whenever I use them Ethernet magic packets wake them immediately. The Intel E-cores are quite good for mostly integer workloads, like code compilation, or for file servers or Web servers, so for such tasks the Intel CPUs are adequate (but ECC-supporting MBs for them are quite expensive). On the other hand their floating-point performance is quite poor (and the P-cores are few and intentionally crippled), so for such workloads AMD Zen 4 is much better, especially for running non-legacy programs, which have been updated and optimized for the modern ISAs.
      - nextos 3y ago
        I thought the idle consumption difference was much larger than 15 W. Do you have any links to reliable benchmarks?
- BackBlast 3y ago
  Arguably you can buy the mobile variants of the Ryzen 7000 series, like 7940HS/7840HS, as a package, cheaper per core than the 7950X. Depending on the use case it may be a better fit. Definitely if footprint and/or power consumption are main drivers it may be much better. If you need the I/O or full ECC of the bigger systems then you just need the bigger systems.

by vinc 3y ago

adrian_b 3y ago

The best performance per dollar in a server for now is if it is built with desktop AMD Ryzen 7000 CPUs, e.g. Ryzen 9 7950X, whose performance per dollar is vastly better than that of any Intel Sapphire Rapids or AMD Genoa or Bergamo or Threadripper. (There are easily available AM5 motherboards with ECC support, and network cards up to those with dual 25 Gb/s ports in SFP connectors are also cheap.) Ryzen 7000 CPUs are not the best only when the performance of the CPU is less important than having a lot of PCIe lanes and/or memory concentrated in a single box, instead of being distributed in multiple boxes (for the latter case multiple Ryzen 7000 boxes are cheaper than a single big server with the same total amount of memory and total count of PCIe lanes). For a lot of memory and PCIe lanes in a single box, there are some Sapphire Rapids models with few cores that are quite cheap, but of course the Intel marketing has decided to cripple them by limiting their memory speed to DDR5-4400. The ubiquitous crippling of the cheap Intel SKUs is intended to force their customers to buy the SKUs with outrageous prices, but all that this has ever done to me was to force me to buy from their competition. For the same purpose, AMD Siena CPUs are expected to be competitive, but only if they will become available at retail, which is uncertain.

alberth 3y ago
I wish more web hosts offered Ryzen 7000s to lease. Hetzner, OVH and Contabo are some of the only few I’m aware of who does.
zamadatix 3y ago
Is it nefarious marketing or just that a lower end CPU with 8 memory channels doesn't need a whizzbang memory controller to get the memory capacity/performance it needs? Besides, doesn't the platinum version only go to 4800 MHz anyways? (split comment to separate topics)
- adrian_b 3y ago
  Decreasing the DDR5 transfer rate from 4800 MHz to 4400 MHz may provide a minuscule improvement in Intel's CPU die yields, supposing that their manufacturing process is bad and it barely allows to reach the standard 4800 MHz frequency, which might be justified as allowing lower prices for the low-end SKUs. The users certainly do not want such a speed reduction, especially taking into account that they will usually buy standard DDR5-4800 modules, which will never be used at the performance that they have been paid for. It is very unlikely that the manufacturing cost reduction due to a relaxed specification for the memory controller is important. Cutting whatever features they could in the cheap SKUs, to annoy the customers (like disabling instruction subsets, and in Sapphire Rapids disabling the accelerators), has been the MO of Intel already for decades.
  - zamadatix 3y ago
    I'm not saying people directly want lower memory clocks rather I'm saying 4000/4400/4800 MHz doesn't seem to be a decision based on intentionally aiming to create upsell segmentation because 400 MHz of memory bandwidth on an 8 channel system is a completely irrelevant way to incentivize people while using lower quality binning and manufacturing to compete on price IS an incentive people in that range want, even if it comes at a minor cost in performance (that's the point of the low end SKUs!). E.g. Epyc segments memory performance in the Edge line by cutting the number of memory channels in HALF, the equivalent of dropping to 2400 MHz speed in a loaded server. Now there are other additional reasons that's actually attractive to buyers as well, namely the Edge class is expected to be lower power and driving 12 channels of high speed memory is counter to that goal, but it gives an idea of how miniscule 400 MHz of memory bandwidth is in terms of things that matter for low tier server performance. If anything I'd say that Epyc has support for 12 memory channels (win of the dedicated I/O die) is leaps and bounds more relevant. The Intel SKUs would need to run their 8 channels at 7200 MHz just to break even and here we are talking about 4400 MHz instead of 4800 MHz as a deciding reason to not buy an Intel server! Every manufacturer has the MO of artificially cutting features to segment things. Intel, AMD, Nvidia, Apple - all of them. Now maybe the folks at Intel marketing were smoking something funny that day and genuinely though this limitation would actually create incentive to go to a higher tier, who knows. Even then, why would that particular (poor) segmentation be a driver be worth choosing to exclude a brand over when the meaningful segments from all players are all much larger?
zamadatix 3y ago
You can get a 14900k with better performance (single core and multi core) for cheaper. Between my 7950X system and that I've found the Intel memory controller to handle higher RAM capacities speeds as well. It also comes with ECC support if you get the right motherboard and you get additional usable PCIe bandwidth over what the 7950X will expose.
- nextos 3y ago
  Also Intel CPUs have much lower consumption while idling, right? As much as I like AMD, I find this a significant advantage for a workstation / small server.
  - adrian_b 3y ago
    It is true that the desktop Intel CPUs have lower idle consumption, usually by 10 to 15 W, than the desktop AMD CPUs. On the other hand, for any given performance at full load, the AMD CPUs have a much lower power consumption, as low as two thirds. Which is preferable depends on the application. For a personal computer, idle power consumption may be the most important. For a server, the power consumption when used is normally more important. I have several servers in my home, which are used intermittently. Their idle power consumption does not matter much, because whenever they are not used they are shut down. Wake-on-Ethernet is enabled on them, and whenever I use them Ethernet magic packets wake them immediately. The Intel E-cores are quite good for mostly integer workloads, like code compilation, or for file servers or Web servers, so for such tasks the Intel CPUs are adequate (but ECC-supporting MBs for them are quite expensive). On the other hand their floating-point performance is quite poor (and the P-cores are few and intentionally crippled), so for such workloads AMD Zen 4 is much better, especially for running non-legacy programs, which have been updated and optimized for the modern ISAs.
    - nextos 3y ago
      I thought the idle consumption difference was much larger than 15 W. Do you have any links to reliable benchmarks?
BackBlast 3y ago
Arguably you can buy the mobile variants of the Ryzen 7000 series, like 7940HS/7840HS, as a package, cheaper per core than the 7950X. Depending on the use case it may be a better fit. Definitely if footprint and/or power consumption are main drivers it may be much better. If you need the I/O or full ECC of the bigger systems then you just need the bigger systems.