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I can’t believe there are CPUs that cost $8k. Does it really pay off price/performance wise or is it just for people that like hot rods?

chrisseaton 5y ago
Are you disbelieving because you think most people would use multiple cheaper CPUs instead? There are some workloads where inter-core communication is the bottleneck, so people pay a premium to get a lot of cores in one place.
can16358p 5y ago
Many of them are for datacenters/cloud computing or rendering services/hypervisors. For them yes they do pay the price for sure, given that the CPU time is utilized efficiently.
PragmaticPulp 5y ago
It’s not for consumers. It’s for special-purpose servers and workstations. Many problems don’t scale well to more nodes. In many cases, it’s worth spending a lot on a single, very expensive server to avoid having to rewrite the software to be distributed across multiple machines.
wongarsu 5y ago
The first "bestselling" consumer CPU I checked costs ~$50/core (a 6core AMD Ryzen 5600X). Scaled to 128 cores that Ryzen would cost $6400. Considering how many motherboards, PSUs, Fans, etc. you safe by having one computer with 128-core CPU compared to 8.3 computers with a 6-core CPU each, the price premium pays for itself (for workloads where this CPU performs at least as well as 8.3 Ryzen 5600X).
- JohnJamesRambo 5y ago
  Is ram, heat, and network I/O not an issue with 128 cores in one box?
  - wongarsu 5y ago
    It can be a problem, or unlock efficiencies. 8x1Gbit vs 1x10Gbit LAN costs about the same, but having the 10Gbit LAN in one box gives you better burst performance than scattering your I/O across 8 boxes. Having all the RAM in one place might reduce how much RAM you need in total. But if you need huge amounts of RAM or network I/O, scattering it across many boxes is probably easier and cheaper. The heat from this CPU is fairly reasonable (about a RTX3070, to stay in consumer comparisons). It pays for that with low clock speed, so your workload has to somehow profit from having all the cores in one place.
    - JohnJamesRambo 5y ago
      Thanks for all the great info!

chrisseaton 5y ago

Are you disbelieving because you think most people would use multiple cheaper CPUs instead? There are some workloads where inter-core communication is the bottleneck, so people pay a premium to get a lot of cores in one place.

can16358p 5y ago

Many of them are for datacenters/cloud computing or rendering services/hypervisors. For them yes they do pay the price for sure, given that the CPU time is utilized efficiently.

PragmaticPulp 5y ago

It’s not for consumers. It’s for special-purpose servers and workstations. Many problems don’t scale well to more nodes. In many cases, it’s worth spending a lot on a single, very expensive server to avoid having to rewrite the software to be distributed across multiple machines.

wongarsu 5y ago

The first "bestselling" consumer CPU I checked costs ~$50/core (a 6core AMD Ryzen 5600X). Scaled to 128 cores that Ryzen would cost $6400. Considering how many motherboards, PSUs, Fans, etc. you safe by having one computer with 128-core CPU compared to 8.3 computers with a 6-core CPU each, the price premium pays for itself (for workloads where this CPU performs at least as well as 8.3 Ryzen 5600X).

JohnJamesRambo 5y ago
Is ram, heat, and network I/O not an issue with 128 cores in one box?
- wongarsu 5y ago
  It can be a problem, or unlock efficiencies. 8x1Gbit vs 1x10Gbit LAN costs about the same, but having the 10Gbit LAN in one box gives you better burst performance than scattering your I/O across 8 boxes. Having all the RAM in one place might reduce how much RAM you need in total. But if you need huge amounts of RAM or network I/O, scattering it across many boxes is probably easier and cheaper. The heat from this CPU is fairly reasonable (about a RTX3070, to stay in consumer comparisons). It pays for that with low clock speed, so your workload has to somehow profit from having all the cores in one place.
  - JohnJamesRambo 5y ago
    Thanks for all the great info!