New 18 Core CPU and NVMe

I just got a E5-2696 v3 CPU for my ML110 Gen9 home workstation, this has a Passmark score of 23326 which is almost 3 times faster than the E5-2620 v4 which rated 9224. Previously it took over 40 minutes real time to compile a 6.10 kernel that was based on the Debian kernel configuration, now it takes 14 minutes of real time, 202 minutes of user time, and 37 minutes of system CPU time. That’s a definite benefit of having a faster CPU, I don’t often compile kernels but when I do I don’t want to wait 40+ minutes for a result. I also expanded the system from 96G of RAM to 128G, most of the time I don’t need so much RAM but it’s better to have too much than too little, particularly as my friend got me a good deal on RAM. The extra RAM might have helped improve performance too, going from 6/8 DIMM slots full to 8/8 might help the CPU balance access.

That series of HP machines has a plastic mounting bracket for the CPU, see this video about the HP Proliant Smart Socket for details [1]. I was working on this with a friend who has the same model of HP server as I do, after buying myself a system I was so happy with it that I bought another the same when I saw it going for a good price and then sold it to my friend when I realised that I had too many tower servers at home. It turns out that getting the same model of computer as a friend is a really good strategy so then you can work together to solve problems with it. My friend’s first idea was to try and buy new clips for the new CPUs (which would have delayed things and cost more money), but Reddit and some blog posts suggested that you can just skip the smart-socket guide clip and when the chip was resting in the socket it felt secure as the protrusions on the sides of the socket fit firmly enough into the notches in the CPU to prevent it moving far enough to short a connection. Testing on 2 systems showed that you don’t need the clip. As an aside it would be nice if Intel made every CPU that fits a particular socket have the same physical dimensions so clips and heatsinks can work well on all CPUs.

The TDP of the new CPU is 145W and the old one was 85W. One would hope that in a server class system that wouldn’t make a lot of difference but unfortunately the difference was significant. Previously I could have the system running 7/8 cores with BOINC 24*7 and I wouldn’t notice the fans being louder. It is possible that 100% CPU use on a hot day might make the fans sound louder if I didn’t have an air-conditioner on that was loud enough to drown them out, but the noteworthy fact is that with the previous CPU the system fans were a minor annoyance. Now if I have 16 cores running BOINC it’s quite loud, the sort of noise that makes most people avoid using tower servers as workstations! I’ve found that if I limit it to 4 or 5 cores then the system is about as quiet as it was before. As a rough approximation I can use as much CPU power as before without making the fans louder but if I use more CPU power than was previously available it gets noisy.

I also got some new NVMe devices, I was previously using 2*Crucial 1TB P1 NVMes in a BTRFS RAID-1 and now I have 2*Crucial 1TB P3 NVMes (where P1 is the slowest Crucial offering, P3 is better and more expensive, P5 is even better, etc). When doing the BTRFS migrations to move my workstation to new NVMe devices and my server to the old NVMe devices I found that the P3 series seem to have a limit of about 70MB/s for sustained random writes and the P1 series is about 35MB/s. Apparently with the cheaper NVMe devices they slow down if you do lots of random writes, pity that all the review articles talking about GB/s speeds don’t mention this. To see how bad reviews are Google some reviews of these SSDs, you will find a couple of comment threads on places like Reddit of them slowing down with lots of writes and lots of review articles on well known sites that don’t mention it. Generally I’d recommend not upgrading from P1 to P3 NVMe devices, the benefit isn’t enough to cover the effort. For every capacity of NVMe devices the most expensive devices cost more than twice as much as the cheapest devices, and sometimes it will be worth the money. Getting the most expensive device won’t guarantee great performance but getting cheap devices will guarantee that it’s slow.

It seems that CPU development isn’t progressing as well as it used to, the CPU I just bought was released in 2015 and scored 23,343 according to Passmark [2]. The most expensive Intel CPU on offer at my local computer store is the i9-13900K which was released this year and scores 62,914 [3]. One might say that CPUs designed for servers are different from ones designed for desktop PCs, but the i9 in question has a “TDP Up” of 253W which is too big for the PSU I have! According to the HP web site the new ML110 Gen10 servers aren’t sold with a CPU as fast as the E5-2696 v3! In the period from 1988 to about 2015 every year there were new CPUs with new capabilities that were worth an upgrade. Now for the last 8 years or so there hasn’t been much improvement at all. Buy a new PC for better USB ports or something not for a faster CPU!

Comments are closed.