> Once network IO became the main bottleneck, the faster CPU mattered less.
It is surprisingly hard to keep a modern CPU core properly saturated unless you are baking global illumination, searching primes or mining crypto currency. I/O and latency will almost always dominate at scale. Moving information is way more expensive than processing it.
furkansahin · 1h ago
Certainly! That was the main reason why we decided to try postgres benchmarking tbh
nine_k · 1h ago
Big machines already are more like clusters (NUMA), where access to memory outside a core's domain is much slower. I suspect compute will be more and more dispersed within RAM.
Transputers just came 30+ years too early.
cma · 1h ago
Some major game engines still have large single thread bottlenecks. They aren't fundamental to the problem space though, more just from legacy engine design decisions.
SkiFire13 · 53m ago
Being single thread bottlenecked doesn't mean they are actually saturating a CPU core, it may likely be waiting for data from RAM for a lot if not most of the time.
Aurornis · 1h ago
AMD’s fastest consumer CPUs are a great value for small servers. If you’re doing just one task (like in this article) the clock speed is a huge benefit.
The larger server grade parts start to shine when the server is doing a lot of different things. The extra memory bandwidth helps keep the CPU fed and the higher core count reduces the need for context switching because your workloads aren’t competing as much.
The best part about the AMD consumer CPUs is that you can even use ECC RAM if you get the right motherboard.
AnimalMuppet · 8m ago
Wait, what? ECC RAM for a consumer CPU? Does anyone sell motherboards like that?
kllrnohj · 40s ago
Literally first Asrock motherboard I happened to click on has it listed as a feature:
I think it was more rare when AM5 first came out, there were a bunch of ECC supported consumer boards for AM4 and threadripper.
dcm360 · 1m ago
Asrock Rack and Supermico sell AM4/AM5 motherboards with support for ECC UDIMMs. Other vendors might state official support on workstation-class motherboards, and in general it might work even on motherboards without official support.
This is certainly interesting, and is something I often wonder about. In our case we mostly run Kubernetes clusters on EX130 servers (Xeon, 24c, 256GB). In this situation there are a lot of processes running, for which increased cores-count and memory availability seems worth it. Particularly when we have the cost of 10-25g private networking for each server, lower node counts seems to come out being more economical.
But, but with fewer processes I can totally believe this works out to be the better option. Thank you for the write-up!
furkansahin · 3h ago
Thanks for the comment! Yeah, if you are using the servers dedicated to yourself and considering the larger server packs more, it definitely makes sense.
In our case, though, if we provide 1/48 of 10Gbit network, it really doesn't work for our end customers. So, we're trying to provide the VMs from smaller but more up-to-date lineup.
justsomehnguy · 1h ago
> In this situation there are a lot of processes running, for which increased cores-count and memory availability seems worth it.
It's always the workload type. For the mixed environments (some with a heavy constant load while the other have only some occasional spikes) the increase of RAM per node is the most important part what allowed us to actually decrease the node count. The whole racks with multiple switches was replaced by a single rack with a modest amount of servers and a single stacked switch.
chicagojoe · 56m ago
Consumer grade CPUs aren't meant to be pushed with heavy load 24/7, meaning, durability becomes another variable which, in my experience, will quickly outweigh the brief burst of speed.
toast0 · 44m ago
AMD uses the same chiplets for Epyc and Ryzen. The packaging is different, and the I/O dies are different, but whatever.
If you really care, you can buy an Epyc branded AM4 or AM5 cpu which has remarkably similar specifications and MSRP to Ryzen offerings.
wmf · 50m ago
If your software can handle machine failures, 20% extra performance is absolutely worth some extra failures.
magicalhippo · 4h ago
Well from what I can see the faster one also has 3D V-cache, so not apples to apples.
That said, at such low core count the primary Epyc advantage is PCIe lanes no?
furkansahin · 4h ago
Yes, you're right but we tried to keep the workloads less cache dependent.
Also, EPYC's PCIe advantage doesn't hold for the Hetzner provided server setup unfortunately because the configurator allows the same number of devices to be attached to both servers.
It is surprisingly hard to keep a modern CPU core properly saturated unless you are baking global illumination, searching primes or mining crypto currency. I/O and latency will almost always dominate at scale. Moving information is way more expensive than processing it.
Transputers just came 30+ years too early.
The larger server grade parts start to shine when the server is doing a lot of different things. The extra memory bandwidth helps keep the CPU fed and the higher core count reduces the need for context switching because your workloads aren’t competing as much.
The best part about the AMD consumer CPUs is that you can even use ECC RAM if you get the right motherboard.
https://www.asrock.com/mb/AMD/X870%20Taichi%20Creator/index....
Asus has options as well such as https://www.asus.com/motherboards-components/motherboards/pr...
I think it was more rare when AM5 first came out, there were a bunch of ECC supported consumer boards for AM4 and threadripper.
But, but with fewer processes I can totally believe this works out to be the better option. Thank you for the write-up!
In our case, though, if we provide 1/48 of 10Gbit network, it really doesn't work for our end customers. So, we're trying to provide the VMs from smaller but more up-to-date lineup.
It's always the workload type. For the mixed environments (some with a heavy constant load while the other have only some occasional spikes) the increase of RAM per node is the most important part what allowed us to actually decrease the node count. The whole racks with multiple switches was replaced by a single rack with a modest amount of servers and a single stacked switch.
If you really care, you can buy an Epyc branded AM4 or AM5 cpu which has remarkably similar specifications and MSRP to Ryzen offerings.
That said, at such low core count the primary Epyc advantage is PCIe lanes no?
Also, EPYC's PCIe advantage doesn't hold for the Hetzner provided server setup unfortunately because the configurator allows the same number of devices to be attached to both servers.