In May 2021 I bought a ML110 Gen9 to use as a deskside workstation [1]. I started writing this post in April 2022 when it had been my main workstation for almost a year. While this post was in a draft state in Feb 2023 I upgraded it to an 18 core E5-2696 v3 CPU [2]. It’s now March 2025 and I have replaced it.
Table of Contents
Hardware Issues
My previous state with this was not having adequate cooling to allow it to boot and not having a PCIe power cable for a video card. As an experiment I connected the CPU fan to the PCIe fan power and discovered that all power and monitoring wires for the CPU and PCIe fans are identical. This allowed me to buy a CPU fan which was cheaper ($26.09 including postage) and easier to obtain than a PCIe fan (presumably due to CPU fans being more commonly used and manufactured in larger quantities). I had to be creative in attaching the CPU fan as it’s cable wasn’t long enough to reach the usual location for a PCIe fan. The PCIe fan also required a baffle to direct the air to the right place which annoyingly HP apparently doesn’t ship with the low end servers, so I made one from a Corn Flakes packet and duct tape.
The Wikipedia page listing AMD GPUs lists many newer ones that draw less than 80W and don’t need a PCIe power cable. I ordered a Radeon RX560 4G video card which cost $246.75. It only uses 8 lanes of PCIe but that’s enough for me, the only 3D game I play is Warzone 2100 which works well at 4K resolution on that card. It would be really annoying if I had to just spend $246.75 to get the system working, but I had another system in need of a better video card which had a PCIe power cable so the effective cost was small. I think of it as upgrading 2 systems for $123 each.
The operation of the PCIe video card was a little different than non-server systems. The built in VGA card displayed the hardware status at the start and then kept displaying that after the system had transitioned to PCIe video. This could be handy in some situations if you know what it’s doing but was confusing initially.
Booting
One insidious problem is that when booting in “legacy” mode the boot process takes an unreasonably long time and often hangs, the UEFI implementation on this system seems much more reliable and also supports booting from NVMe.
Even with UEFI the boot process on this system was slow. Also the early stage of the power on process involves fans being off and the power light flickering which leads you to think that it’s not booting and needs to have the power button pressed again – which turns it off. The Dell power on sequence of turning most LEDs on and instantly running the fans at high speed leaves no room for misunderstanding. This is also something that companies making electric cars could address. When turning on a machine you should never be left wondering if it is actually on.
Noise
This was always a noisy system. When I upgraded the CPU from an 8 core with 85W “typical TDP” to an 18 core with 145W “typical TDP” it became even louder. Then over time as dust accumulated inside the machine it became louder still until it was annoyingly loud outside the room when all 18 cores were busy.
Replacement
I recently blogged about options for getting 8K video to work on Linux [3]. This requires PCIe power which the z640s have (all the ones I have seen have it I don’t know if all that HP made have it) and which the cheaper models in the ML-110 line don’t have. Since then I have ordered an Intel Arc card which apparently has 190W TDP. There are adaptors to provide PCIe power from SATA or SAS power which I could have used, but having a E5-2696 v3 CPU that draws 145W [4] and a GPU that draws 190W [4] in a system with a 350W PSU doesn’t seem viable.
I replaced it with one of the HP z640 workstations I got in 2023 [5].
The current configuration of the z640 has 3*32G RDIMMs compared to the ML110 having 8*32G, going from 256G to 96G is a significant decrease but most tasks run well enough like that. A limitation of the z640 is that when run with a single CPU it only has 4 DIMM slots which gives a maximum of 512G if you get 128G LRDIMMs, but as all DDR4 DIMMs larger than 32G are unreasonably expensive at this time the practical limit is 128G (which costs about $120AU). In this case I have 96G because the system I’m using has a motherboard problem which makes the fourth DIMM slot unusable. Currently my desire to get more than 96G of RAM is less than my desire to avoid swapping CPUs.
At this time I’m not certain that I will make my main workstation the one that talks to an 8K display. But I really want to keep my options open and there are other benefits.
The z640 boots faster. It supports PCIe bifurcation (with a recent BIOS) so I now have 4 NVMe devices in a single PCIe slot. It is very quiet, the difference is shocking. I initially found it disconcertingly quiet.
The biggest problem with the z640 is having only 4 DIMM sockets and the particular one I’m using has a problem limiting it to 3. Another problem with the z640 when compared to the ML110 Gen9 is that it runs the RAM at 2133 while the ML110 runs it at 2400, that’s a significant performance reduction. But the benefits outweigh the disadvantages.
Conclusion
I have no regrets about buying the ML-110. It was the only DDR4 ECC system that was in the price range I wanted at the time. If I knew that the z640 systems would run so quietly then I might have replaced it earlier. But it was only late last year that 32G DIMMs became affordable, before then I had 8*16G DIMMs to give 128G because I had some issues of programs running out of memory when I had less.
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