Optimizing Thread Allocation on Older Enterprise Hardware (ProLiant DL360 / 14-Core Xeon)

[wevaba6950]

Hi everyone,
I’ve been a long-time folder on my main gaming rig, but I recently decided to shift the heavy lifting to a more permanent setup. I managed to get my hands on some enterprise surplus—a ProLiant DL360 equipped with a 14-core 2GHz Xeon. It’s a different experience compared to the high-clocked consumer chips I'm used to, especially when it comes to the sheer volume of threads available.
I’ve been digging through the forum archives, and one specific point I saw mentioned in a previous technical thread was the "Prime Number" issue—where certain core counts can cause the Gromacs cores to struggle with domain decomposition. With 14 physical cores (or 28 threads with Hyper-Threading), I’m trying to figure out the best way to map this out in the client to avoid any performance penalties.
From my short time testing this server, I’ve noticed that while it's incredibly stable, the lower 2.0GHz clock speed means the Time Per Frame (TPF) can be quite high on larger work units. I’m torn between running one massive SMP slot to utilize the whole CPU or splitting the workload into two smaller slots to ensure that a single "stuck" work unit doesn't stall the entire machine's output. It’s a bit of a learning curve moving from a 5GHz i9 to a server that relies purely on parallelization rather than raw speed.
I’m really focused on contributing as much as possible to the research, but I want to make sure I’m not just spinning the fans and wasting power if the thread count is poorly optimized.
In your experience with these mid-range Xeon builds, do you find it more efficient to let the client handle all cores in one go, or is there a specific "sweet spot" thread count that handles work units more reliably at these lower frequencies?

[Joe_H]

I have approved your post even though you have multiple spam reports on the chance you are genuinely interested in folding and not just advertising the seller of used servers at the link I have removed.

Some of the info you dug up was valid for older CPU folding cores, multiples of "large" primes could cause issues. That is no longer the case with the CPU folding cores currently in use though there can be efficiency peaks depending on the number of CPU threads and which specific projects are being processed.

With the 14-core Xeon you have at least a processor that is modern enough to support AVX and AVX2, that gives a boost to processing speed. The Xeon also supports HT resulting in up to 28 threads being available. However using the extra threads available through HT may not increase WU processing throughput as much, it does increase power usage and can result in thermal throttling. So I would recommend starting with a thread count of 14 and doing some experimentation with different counts to see what gives the best results for you.