What's the best configuration of mprime for dual CPUs?

[drkirkby]

After installing the 2nd CPU I was tired and could not be bothered to run the benchmark, but I set off 3 workers, each doing an almost identical exponent.



* 24 cores - estimated time to complete 8 days
* 12 cores - estimated time to complete 6 days

* 12 cores - estimated time to complete 8 days


I have a real problem in this machine, that the memory is not configured optimally, but an attempt to put one DIMM/channel on the first CPU results in a machine which will not power on. I think its a motherboard fault. Unfortunately I am stuck between a rock and a hard place


* Dell computer, supplied with 2 x 8 GB DIMMs, still under warrenty.

* 7 x 32 GB Kingston DIMMS


It's going to be tricky to get Dell to do anything about this, as it needs 4 DIMMs to display the fault, and I don't have 4 Dell DIMMs. Dell charge a ****ing fortune for memory. I'm reluctant to buy two 8 GB DIMMs just to prove a point, when I don't want to use 8 GB DIMMS anyway.



The RAM performance on this machine is pretty dire at the moment.



Dave

[VBCurtis]

I don't get that you complain about the cost of memory, but won't buy 8GB dimms. If you're mostly using the box to search for primes, 32GB per socket is overkill already, never mind trying to load it with 32GB dimms.

I don't see how you'd have any claim with Dell when you bought CPUs that are almost surely not officially supported by their motherboard.

You get what you pay for, and you bought CPUs whose price was too good to be true.

[drkirkby]

Originally Posted by VBCurtis

I don't get that you complain about the cost of memory, but won't buy 8GB dimms. If you're mostly using the box to search for primes, 32GB per socket is overkill already, never mind trying to load it with 32GB dimms.

I don't see how you'd have any claim with Dell when you bought CPUs that are almost surely not officially supported by their motherboard.

You get what you pay for, and you bought CPUs whose price was too good to be true.

The machine has real work to do - searching for primes is not its main task. I can reproduce the fault using just the one original CPU from Dell. However, I can't reproduce the fault with the two pieces of RAM supplied by Dell - I need 4 pieces of RAM to show the fault.

The reason I complain about the cost of the RAM is that a single 8 GB DIMM from Dell costs about 25% more than a 32 GB DIMM from Kingston. So the Dell DIMMs are 25% of the capacity of the Kingston ones, but 125% of the cost!