Hi Everyone,
When looking to buy an Epyc system from ebay I noticed that Gen 2 Rome CPUs and motherboards (for example: AMD EPYC 7452 CPU + Supermicro H12SSL-i) were often sold bundled with 2133Mhz DDR4. My initial reaction was to completely disregard these offerings because the standard on desktop is now 3200 and above for AM4. 2133 DDR is unthinkable these days.
I could not find 3200 DDR4 included in the CPU and motherboard kits at a price to fit my budget. So I reconsidered my aversion to 2133 and looked again at my use case. It seems like 2133 is not so much of an issue on multi-core server systems with eight channels that aren't going to perform under high utilisation.
My aim is to build a power efficient virtualisation platform that will host a few persistent services (as either VMs or System Containers aka LXD) and labs for Cisco/Juniper/Arista infrastructure and linux based cloud infrastructure. None of these VMs will place compute or bandwidth demand on the system and really they just require free cores and RAM. The network labs spin up numerous virtual instances which will likely make the biggest demand.
This server will also virtualise a modest NVME based Truenas installation that will install ZFS on NVME SSDs passed through from the host. This will pretty much idle most of the time and most operations will be light.
Because this server will be configured as much as possible to be power efficient at idle and low use it may be that 2133 DDR will provide all the memory performance it needs, especially if all eight DIMM slots are populated.
The motherboard will be a Supermicro H12SSL-i and the CPUs I'm considering are Rome:
- Epyc 7352
- Epyc 7452
- Epyc 7402
The other consideration is whether or not TDP and Base clock should be factors to use to help determine low power efficiency of a particular SKU. Part of my reasoning has been to consider a low Base clock to be more desirable than a higher Base. Same with TDP. However, I'm not sure that it is valid reasoning to think that two CPUs with the same Core count but different TDPs cannot both idle at low power. A 32 core 200w CPU and a 32 core 155w CPU might both have similar idle and low utilisation power behaviour but one will boost higher when demand requires it (more headroom).
My questions then are:
1. for a modest duty (lots of small VM/System Containers) network/cloud "homelab" would cheap 2133 DDR4 be an excellent value proposition?
2. when considering CPUs with desirable core count and cache (looking at cache it seems that 7002 SKUs share similar cache/core design) is it incorrect to disregard higher TDP SKUs as being incompatible for low power applications (again, a homelab running lots of small virtualized loads)?
If YES to both questions I will be able to consider more CPU, Motherboard and RAM combinations that might fit my budget. It seems that on the Chinese Ebay sites (like tugm4470) a few of the high TDP SKUs are more plentiful and therefore cheaper). Thanks!
When looking to buy an Epyc system from ebay I noticed that Gen 2 Rome CPUs and motherboards (for example: AMD EPYC 7452 CPU + Supermicro H12SSL-i) were often sold bundled with 2133Mhz DDR4. My initial reaction was to completely disregard these offerings because the standard on desktop is now 3200 and above for AM4. 2133 DDR is unthinkable these days.
I could not find 3200 DDR4 included in the CPU and motherboard kits at a price to fit my budget. So I reconsidered my aversion to 2133 and looked again at my use case. It seems like 2133 is not so much of an issue on multi-core server systems with eight channels that aren't going to perform under high utilisation.
My aim is to build a power efficient virtualisation platform that will host a few persistent services (as either VMs or System Containers aka LXD) and labs for Cisco/Juniper/Arista infrastructure and linux based cloud infrastructure. None of these VMs will place compute or bandwidth demand on the system and really they just require free cores and RAM. The network labs spin up numerous virtual instances which will likely make the biggest demand.
This server will also virtualise a modest NVME based Truenas installation that will install ZFS on NVME SSDs passed through from the host. This will pretty much idle most of the time and most operations will be light.
Because this server will be configured as much as possible to be power efficient at idle and low use it may be that 2133 DDR will provide all the memory performance it needs, especially if all eight DIMM slots are populated.
The motherboard will be a Supermicro H12SSL-i and the CPUs I'm considering are Rome:
- Epyc 7352
- Epyc 7452
- Epyc 7402
The other consideration is whether or not TDP and Base clock should be factors to use to help determine low power efficiency of a particular SKU. Part of my reasoning has been to consider a low Base clock to be more desirable than a higher Base. Same with TDP. However, I'm not sure that it is valid reasoning to think that two CPUs with the same Core count but different TDPs cannot both idle at low power. A 32 core 200w CPU and a 32 core 155w CPU might both have similar idle and low utilisation power behaviour but one will boost higher when demand requires it (more headroom).
My questions then are:
1. for a modest duty (lots of small VM/System Containers) network/cloud "homelab" would cheap 2133 DDR4 be an excellent value proposition?
2. when considering CPUs with desirable core count and cache (looking at cache it seems that 7002 SKUs share similar cache/core design) is it incorrect to disregard higher TDP SKUs as being incompatible for low power applications (again, a homelab running lots of small virtualized loads)?
If YES to both questions I will be able to consider more CPU, Motherboard and RAM combinations that might fit my budget. It seems that on the Chinese Ebay sites (like tugm4470) a few of the high TDP SKUs are more plentiful and therefore cheaper). Thanks!
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