Dell Optiplex 9020/i7-4770

[garo]

So I got one of these boxes from work as they were retiring old CPUs. Being a Dell there is no option to overclock. I've added an EVO 860 to it and it's crunching away merrily. Is there any thing I can do to improve output? Running doublechecks w/ 2880K FFT.

The CPU runs quite hot and I see 75-78C on psensor. I've also had the computer crash a couple of times but I don't really know why and could find nothing in the logs - Xubuntu 19.10. Saw the graphics do funny stuff once - using the onboard graphics - but the other two times it just froze. Couldn't ssh into it.

Finally, I've run benchies from mprime but I can't seem to get the mersenne website to accept them. My benchmarks have the data for the CPU but all the timing coulumns are blank.

[ewmayer]

Originally Posted by garo

So I got one of these boxes from work as they were retiring old CPUs. Being a Dell there is no option to overclock. I've added an EVO 860 to it and it's crunching away merrily. Is there any thing I can do to improve output? Running doublechecks w/ 2880K FFT.

The CPU runs quite hot and I see 75-78C on psensor. I've also had the computer crash a couple of times but I don't really know why and could find nothing in the logs - Xubuntu 19.10. Saw the graphics do funny stuff once - using the onboard graphics - but the other two times it just froze. Couldn't ssh into it.

What kinds of PCI slots does this system have? You could probably get a multiple of the CPU throughput from installing a well-chosen GPU, assuming the needed PCI slot(s) and physical space permit.

Re. ssh access, did you install [h/t Paul Underwood] openssh-server on top of basic ssh?

[mackerel]

I got a couple of these from work which was throwing them out.

The cooler isn't great but just about adequate. The CPU will be kept within Intel specs anyway. I'd try running some ram verification software just to check that hasn't gone bad.

Performance wise, make sure it has dual channel ram at the least. If the existing ram isn't already dual rank, you could try to fill all 4 slots up as that will give you 2 rank per channel, and boost the ram performance a bit more. I'm not sure how the mobo bios behaves but I'd aim to get modules with SPD programmed at 1600 or higher, not enthusiast kits which might require XMP as it wont use those settings.

On GPU options, there are two PCIe 16x slots, and one 1x slot. I don't know how they're connected. The bigger problem with adding a GPU is the included PSU is really minimal and also non standard connectors. It could be some work to replace it with a higher power ATX unit. As such I you might get away with adding two GPUs that doesn't need an external power connection. Due to the spacing the lower slot can only be use with a single height card. The upper slot can take thicker GPUs.

My system came with a 290W PSU. Two GPUs at 75W each will use 150W. The CPU is rated at 84W TDP and in those days TDP still resembled somewhat the max power usage, so let's round it and say we're up to 250W usage total. That leaves 40W for everything else... assuming you max the CPU and GPUs at the same time. If you're going to be GPU focused and not load the CPU up that'll of course increase headroom.

[PhilF]

Originally Posted by mackerel

My system came with a 290W PSU.

...

That leaves 40W for everything else...

No it doesn't. You can't run a power supply at 80% to 100% of its rated capacity and expect it to last very long.

Unless you can beef up that supply, I would not run 2 75W GPUs in that box.

[chalsall]

Originally Posted by mackerel

The bigger problem with adding a GPU is the included PSU is really minimal and also non standard connectors. It could be some work to replace it with a higher power ATX unit.

To resonate with this... This is why I've stopped deploying Dell's workstations when I have the decision authority. Prefer to use assembled kit where replacement/upgrades are available COTS (and/or between kit in inventory).

On the other hand, I /love/ Dell's rack-mount server offerings. Fantastic on-site support, even here in little Bimshire.

[kriesel]

Originally Posted by PhilF

You can't run a power supply at 80% to 100% of its rated capacity and expect it to last very long.

Amen to that. I've had systems that could run 4 gpus short term (months) drop to 3 and then 2 over time; HP Z600; and Lenovo workstations go from 3 to 2 for example.

[mackerel]

My thinking wasn't so much running the PSU at close to 100% load 24/7, but that the PSU could cope in case you entered that situation at all. If you were to add two GPUs, I'd guess you'd prioritise driving those and not max out the CPU also.

It has been a long time since I've ran any PSU close to its rated power. Even cheaper consumer ones are overpowered for anything I will realistically do with them.

I did run PSUs closer to their limit in the older days when I used to run more crunchers in the single core era. I just viewed them as a consumable. Just get the cheapest one that'll work, and replace as they die after a year or so. Some claim possible damage when a PSU fails, but I've never had that happen. It is more a gradual stability loss.

[ewmayer]

Originally Posted by PhilF

No it doesn't. You can't run a power supply at 80% to 100% of its rated capacity and expect it to last very long.

Unless you can beef up that supply, I would not run 2 75W GPUs in that box.

If the per-watt throughput from the GPUs is expected to be better than for the CPU, just idle the CPU, which should keep the wattage < 200. But, yes, you want whatever workload gives best total throughput while keeping the PSU no more than ~70% of rated wattage.

[garo]

Originally Posted by ewmayer

What kinds of PCI slots does this system have? You could probably get a multiple of the CPU throughput from installing a well-chosen GPU, assuming the needed PCI slot(s) and physical space permit.

Re. ssh access, did you install [h/t Paul Underwood] openssh-server on top of basic ssh?

Yes I have openssh already installed. mackerel describes the system pretty well. There's a Matrox dual display card in there already. I'm not really looking to buy a GPU card though GPU LL output does seem to have come a long way. I have a GTX 580 in another box which is currently shut down but I am going to use this computer for development work so want it to stay reasonably quiet. Prime crunching is a bonus and not the main purpose of the box. Would a 5500 XT be too loud? RX 470?

Originally Posted by mackerel

I got a couple of these from work which was throwing them out.

The cooler isn't great but just about adequate. The CPU will be kept within Intel specs anyway. I'd try running some ram verification software just to check that hasn't gone bad.

Performance wise, make sure it has dual channel ram at the least. If the existing ram isn't already dual rank, you could try to fill all 4 slots up as that will give you 2 rank per channel, and boost the ram performance a bit more. I'm not sure how the mobo bios behaves but I'd aim to get modules with SPD programmed at 1600 or higher, not enthusiast kits which might require XMP as it wont use those settings.

On GPU options, there are two PCIe 16x slots, and one 1x slot. I don't know how they're connected. The bigger problem with adding a GPU is the included PSU is really minimal and also non standard connectors. It could be some work to replace it with a higher power ATX unit. As such I you might get away with adding two GPUs that doesn't need an external power connection. Due to the spacing the lower slot can only be use with a single height card. The upper slot can take thicker GPUs.

You describe the system to a T. I have 4x4GB RAM that came with the box. It is 1333 GHz Hynix so I think I'm getting the most out of it already. The upper slot is currently occupied by the Matrox M9128 card. Great for 2D but useless for computing. The lower slot is empty. I have a Radeon HD3470 spare but that's also useless. I'll see if I can get a cheap GPU.

In the meantime, any other configuration/optimization settings to tweak?

[garo]

Ok so new development. System just crashed. Had been running for a day and a half without any problem. The screen went strange - looked like a GPU issue - it's on the on-board graphics right now. Then the computer powered off and when it tried powering on it beeped once and switched off and then went into a loop. And it won't come on at all now.

I will try reseating the RAM tomorrow and report back.

[ewmayer]

Originally Posted by garo

Ok so new development. System just crashed. Had been running for a day and a half without any problem. The screen went strange - looked like a GPU issue - it's on the on-board graphics right now. Then the computer powered off and when it tried powering on it beeped once and switched off and then went into a loop. And it won't come on at all now.

I will try reseating the RAM tomorrow and report back.

I installed my RadeonVII in my old and already-flaky Haswell quad ATX-case system, that made things even more unstable, getting even 12 hours of uptime was rare. First thought was maybe my aging PSU was not up to the task, so ordered a brand-new Corsair 850W one. While waiting for that to arrive, tried some BIOS tweaks recommened by others - one from George, namely to disable "C-states" (a CPU power-saving thing) via the OC menu, proved to be the cure, been rock-solid ever since, current uptime 18 days. So the new PSU is gonna go into a second multi-GPU system I'm building, around a lightly used 8-core AMD Ryzen 5 1500X CPU/mobo/ram/liquid-cooler bundle obtained on eBay. (Currently waiting on the test-bench frame I'm using as an open-air chassis, delayed nearly a month, apparently due to Covid-19 supply-chain issues.)

Not saying your issue will be in any way similar, just that the symptoms may not be in any way indicative of the source of the problem.