Hi,
Quick summary: I have a dual CPU HP z840 which is too powerful. I would like to downgrade to save power. Wonder about the compatibility of the CPUs I plan to replace.
Longer introduction:
Now I basically use that machine as my workstation (Debian 12, KDE) for work. I could repurpose it to become a home server. The problem is that this HP z840 is too power hungry. Measuring with a watt meter at the wall, it idles at 60W. When working it fluctuates between 125 - 170W. I have modest needs for home server, for which I currently use a more power efficient machine.
I like that HP z840 and would like to continue to use it as workstation. But I would like to reduce the power consumption. The main usage is programing, scripting. I rarely use more than 16GB of ram, the CPUs are mostly idle most of the time. The most intensive tasks is when I run temporarily a linux VM or two with KVM.
QUESTIONS
Q1. Is it OK to replace the two E5-2678 v3 by one E6-2620 v4 (8 phys cores) or one E6-2630 v4 (10 phys cores). Please note, there is a jump in generation v3 -> v4.
For some reasons, in spite of the 8 vs 10 cores both of these CPUs are rated for a 85W TDP. In this case it would make more sense to go with 10 cores. I am aware that the lack of a 2nd CPU would disable half of the RAM banks and some PCI slots would no longer work.
This is OK, reducing 128 to 64GB ram is plentiful enough for my usage. I use only 2 PCI slots (the adapter for NVMe, video card).
Q2. on eBay, I could find the E5-2620v4 or E5-2630v4 for about $10 from sellers from China, free shipping. Is it legit? Not sure why the price is so low.
Thanks very much for any help
EDIT (answers)
Ordered from eBay 2x E5-2630 v4, stepping SR2R7, $13 for both, free shipping, delivered in a week. Maybe it was on sale, b/c the price is now doubled of what I had ordered.
Replaced the existing 2x E5-2678 v3. Rebooted the HP z840 (bios 2.61, up-to-date as of Aug 2023). The new CPUs are recognized by the BIOS. The BIOS has a hardware diagnostic utility. I ran the 30 minutes CPU test which was successful. Then ran Memtest86+ for 4 hours which also passed.
Overall the computer was working as before. But the goal of hoping to see a significant power consumption reduction is not really there. Luckily for me, it was not a very expensive experiment. The average power consumption is lowered by around 10W. Was 125W now 115W. The usage is typical programming work (no intensive workload), web browsing, Debian 12, KDE.
Looking forward to reducing the power consumption by half when I will run in single CPU mode.
Quick summary: I have a dual CPU HP z840 which is too powerful. I would like to downgrade to save power. Wonder about the compatibility of the CPUs I plan to replace.
Longer introduction:
- HP z840, 2x E5-2678 v3 (2x12 cores = 24 cores, 48 threads), rated 120W per CPU
- 128 GB ram (8x16GB DDR4 ECC)
- 1 NVMe 1TB using an after market adaptor NVMe-PCIe
- low end video card
Now I basically use that machine as my workstation (Debian 12, KDE) for work. I could repurpose it to become a home server. The problem is that this HP z840 is too power hungry. Measuring with a watt meter at the wall, it idles at 60W. When working it fluctuates between 125 - 170W. I have modest needs for home server, for which I currently use a more power efficient machine.
I like that HP z840 and would like to continue to use it as workstation. But I would like to reduce the power consumption. The main usage is programing, scripting. I rarely use more than 16GB of ram, the CPUs are mostly idle most of the time. The most intensive tasks is when I run temporarily a linux VM or two with KVM.
QUESTIONS
Q1. Is it OK to replace the two E5-2678 v3 by one E6-2620 v4 (8 phys cores) or one E6-2630 v4 (10 phys cores). Please note, there is a jump in generation v3 -> v4.
For some reasons, in spite of the 8 vs 10 cores both of these CPUs are rated for a 85W TDP. In this case it would make more sense to go with 10 cores. I am aware that the lack of a 2nd CPU would disable half of the RAM banks and some PCI slots would no longer work.
This is OK, reducing 128 to 64GB ram is plentiful enough for my usage. I use only 2 PCI slots (the adapter for NVMe, video card).
Q2. on eBay, I could find the E5-2620v4 or E5-2630v4 for about $10 from sellers from China, free shipping. Is it legit? Not sure why the price is so low.
Thanks very much for any help
EDIT (answers)
Ordered from eBay 2x E5-2630 v4, stepping SR2R7, $13 for both, free shipping, delivered in a week. Maybe it was on sale, b/c the price is now doubled of what I had ordered.
Replaced the existing 2x E5-2678 v3. Rebooted the HP z840 (bios 2.61, up-to-date as of Aug 2023). The new CPUs are recognized by the BIOS. The BIOS has a hardware diagnostic utility. I ran the 30 minutes CPU test which was successful. Then ran Memtest86+ for 4 hours which also passed.
Overall the computer was working as before. But the goal of hoping to see a significant power consumption reduction is not really there. Luckily for me, it was not a very expensive experiment. The average power consumption is lowered by around 10W. Was 125W now 115W. The usage is typical programming work (no intensive workload), web browsing, Debian 12, KDE.
Looking forward to reducing the power consumption by half when I will run in single CPU mode.
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