A power supply can also put off ALOT of heat especially as the number of cores in use goes up, getting a Gold or above level psu will drastically cut the heat put out by it as well.

Corsair supplies are very efficient, they run under body temperature unless they're loaded to over 50%. None of mine generate any heat, even with a 130W Ryzen. They only gave out heat when I had a GPU on them too.

Agreed. Though mine is a Gold rated one with a lot of overhead. When I specced the build I was warned that the PSU was far more than I needed.

Agreed. Though mine is a Gold rated one with a lot of overhead. When I specced the build I was warned that the PSU was far more than I needed.

Nothing is ever more than you need. As the Chameleon Cable Company says - Always Overkill. https://www.ebay.co.uk/str/chameleoncablecompany That's where I got some 4AWG cable which is as thick as 0AWG. Powering 15 GPUs with it.

Whatever the specs of something says, assume half. 48MP camera, 24 at best. 50mpg from a car, 25 if you're lucky. 8 amp power supply, 5 amps melts it. CPU cooler runs at 60C, you get 90C.

It's generally good to have the headroom. Even though PSUs are rated to run at the highest wattage continuously with additional accounting for current spikes, the conversion efficiency is the best at around 50-75% load. Efficiency drop off on both ends, especially don't go below 20%. 80Plus is measured against 20%, 50% and 100% load, so anything below may not be as good as one thinks.

Manufacturers like Corsair actually publishes efficiency curve for their PSU in the manual if you want to find the right power and operate at the most efficient point.

That's where I got some 4AWG cable which is as thick as 0AWG. Powering 15 GPUs with it.

Wouldn't that just be... 0AWG cable? o.O AWG isn't marketing fluff, it's a technical description of cable cross section.

Even though PSUs are rated to run at the highest wattage continuously with additional accounting for current spikes, the conversion efficiency is the best at around 50-75% load. Efficiency drop off on both ends, especially don't go below 20%. 80Plus is measured against 20%, 50% and 100% load, so anything below may not be as good as one thinks.

Right, PSUs tend to have a broad efficiency peak in the 40-70% range - and you'll see this in power supply reviews. It's worth looking up reviews for PSUs you're considering to see where they peak. Most PSUs are also marginally more efficient on a 240VAC input, vs 120V - so if you have the ability to run them on a higher input voltage, do so.

It's generally good to have the headroom. Even though PSUs are rated to run at the highest wattage continuously with additional accounting for current spikes, the conversion efficiency is the best at around 50-75% load. Efficiency drop off on both ends, especially don't go below 20%. 80Plus is measured against 20%, 50% and 100% load, so anything below may not be as good as one thinks.

Manufacturers like Corsair actually publishes efficiency curve for their PSU in the manual if you want to find the right power and operate at the most efficient point.

If it's Chinese, remember the conversion factor, 2 Chinese amps = 1 British amp. Exceeding the limit will not cause current limiting or shutoff, but smoke.

It's generally good to have the headroom. Even though PSUs are rated to run at the highest wattage continuously with additional accounting for current spikes, the conversion efficiency is the best at around 50-75% load. Efficiency drop off on both ends, especially don't go below 20%. 80Plus is measured against 20%, 50% and 100% load, so anything below may not be as good as one thinks.

Manufacturers like Corsair actually publishes efficiency curve for their PSU in the manual if you want to find the right power and operate at the most efficient point.

I don't seed the point in spending money to save money. I bought a heat pump to save electricity, and it didn't last too long. My neighbour bought one of those fancy condensing gas boilers, it also didn't last too long.

Wouldn't that just be... 0AWG cable? o.O AWG isn't marketing fluff, it's a technical description of cable cross section.

And running a cable at the accepted current for those specs makes it very warm, bad idea. And if it's low voltage, the voltage drop is a pest. So when I buy 4AWG from them, I know it will perform decently at the 4AWG specs.

What is a o.O?

Most PSUs are also marginally more efficient on a 240VAC input, vs 120V - so if you have the ability to run them on a higher input voltage, do so.

Everything is 240V here in the civilised UK. One type of socket with 3.12kW available in every room. No different plugs, no complex house wiring, no balancing loads. I do laugh when someone trips a breaker in America with only two computers.

Most PSUs are also marginally more efficient on a 240VAC input, vs 120V - so if you have the ability to run them on a higher input voltage, do so.VAC input, vs 120V - so if you have the ability to run them on a higher input voltage, do so

Though you would have to take into account the efficiency of converting from 120 to 240V if you don't have the higher voltage supply natively.

If it's Chinese, remember the conversion factor, 2 Chinese amps = 1 British amp. Exceeding the limit will not cause current limiting or shutoff, but smoke.

That would cover pretty much all PSUs, including Corsair's. Not sure what's your point, though I kinda get many of your posts are just trolling at this point...

Though you would have to take into account the efficiency of converting from 120 to 240V if you don't have the higher voltage supply natively.

Even Americans have -120 - 0 - +120 volts. So you have 240V. I believe they're available for "dryer circuits" etc. Or if you have one of those double 120V outlets, you'll probably find one outlet is -120V and one is +120V, so you can change that outlet to a single 240V one by using the two hots.

That would cover pretty much all PSUs, including Corsair's.

No it would not. Decent PC supplies will shut off (preferable for a PC than undervolting) if overloaded, one of my Corsairs did. Decent non-PC supplies are usually current limiting. I have a 12V 83A supply I use for GPUs, and it limits to 83A exactly (I measured it with a clamp meter).

Not sure what's your point, though I kinda get many of your posts are just trolling at this point...

No, it's a factual point, no idea why you think I'm trolling. Most cheap Chinese supplies will give out half what's advertised, then break catastrophically. I ordered a 4A 12V supply for a monitor, I drew just under 4A and it went bang with a cloud of smoke. So I ordered an 8A version. It works at just under 4A although rather hot. Thus for Chinese supplies, just buy double what you need and you'll be fine, and you save a lot of money too.

No it would not. Decent PC supplies will shut off (preferable for a PC than undervolting) if overloaded, one of my Corsairs did. Decent non-PC supplies are usually current limiting. I have a 12V 83A supply I use for GPUs, and it limits to 83A exactly (I measured it with a clamp meter).

Corsair PSUs are great and I used them too. I just mean Corsair PSUs are also manufactured in China, in case you don't know. If you look carefully on the box and label on your PSU, you will see "made in China". The "cheap" is the real problem when coming to PSUs. Good components and designs are simply not going to be cheap (relatively). I probably wouldn't buy the dirt cheap ones even with double of the headroom because PSUs can legitimately be a fire hazard...

Corsair PSUs are great and I used them too. I just mean Corsair PSUs are also manufactured in China, in case you don't know. If you look carefully on the box and label on your PSU, you will see "made in China". The "cheap" is the real problem when coming to PSUs. Good components and designs are simply not going to be cheap (relatively).

There are two sets of people in China, the hard working lot that make the decent stuff we all enjoy, and the ones selling tat on Ebay, like 32GB USB sticks advertised as 2TB because they've been reprogrammed.

I probably wouldn't buy the dirt cheap ones even with double of the headroom because PSUs can legitimately be a fire hazard...

Safety third. Why worry about the unlikely? And you're wrong, all that happens is a capacitor explodes and makes a loud noise. Unless you operate the PSU in the same room you store open canisters of petrol....

Thanks for the quick summary.
1. Where I live, less than 3km from the two Uni campuses (that had multi-terabit bandwidth 12 years ago when I quit there) in this metro area, Gbit Fiber is "not available" to my home.
I might be able to double my upload speed on ADSL at about the same price I'm paying now for 568 kbytes/sec upload. Paying also for coax cable would bring my total upload bandwidth to 2Mbyte or 20mbit for an extra 80 USD/month.
2. Disk space is to totally cheap here now. When the upload fail on CPDN happened all I needed to do was to re-assign some some spare less-than-
terabyte free space. No problem, no cost
3. RAM capacity. I use AMD Ryzen 7 and 9.. They use DDR4 ECC UDIMMS @ 3200. The price of those has dropped fast as DDR5 is newest thing. 64GB 3200 UDIMMS (the least possible RAM for the current oifs models and CPUs with at least 8 cores using only 5 out of 8.) now way less than 300 USD at NEMIX.com. I'll buy another 64G soon, before they run out of stock.Memory speed has little effect on oifs jobs so far in my experience. Memory space can, and has, wasted some workunits for me. Like when I allowed 5 oifs to run on a AMD 5900X with only 32G ECC UDIMMS. And no swap space. The dreaded OOM-killer. Not good.

So, for me here, Disk and RAM getting cheaper, internet bandwidth upload unavailable, CPUs relatively cheap. I'm gonna ask my kid who lives on the edge of a barrio, who I think said that they have gigabit fiber up and down.
Only in the USA :(

xii5ku wrote:

Hardware requirements for current "OpenIFS 43r3 Perturbed Surface" work:

The following items need to be taken into account, in descending order of concern:
1. Upload bandwidth of your internet link.
2. Disk space.
3. RAM capacity.
99. CPU. This one doesn't really matter, except of course that CPU core count has got an influence on how many tasks you may want to run in parallel, and that core count × core speed influences how many tasks you can complete per day at most. One or both of these factors (concurrent tasks, average rate of task completions) influence the sizing of items 1…3 in this list.

Note, I bolded one word in the first sentence after the fact.

This priority order has been criticised here. I admit that my perspective is somewhat biased, as I am owning several computers with relatively high core count and high computational throughput and am used to be able to fully utilize them. (Although that's not always trivial to accomplish, because many BOINC projects are focused on low core count/ low throughput hosts.)

However, given how the current "OpenIFS 43r3 Perturbed Surface" campaign is going so far, my priority list is – empirically; refer to thread 9167, thread 9178 – indeed quite generally applicable.

current

---

And running a cable at the accepted current for those specs makes it very warm, bad idea. And if it's low voltage, the voltage drop is a pest. So when I buy 4AWG from them, I know it will perform decently at the 4AWG specs.

Again... I don't understand your point here. If I decide I want 0AWG, I buy 0AWG from a supplier. If I am fine with 4AWG, I buy 4AWG. These are technical descriptions of wire. If I ordered 4AWG and got 0AWG instead, I'd send it back as the wrong product, because it wouldn't fit in my cable terminators (typically). If you need to keep the temperature rise on a run down, you spec the proper cable for it, though even the cheap stuff is rated to 60C insulation temps, with most stuff being rated to 90C.

What is a o.O?

Confused look. Raised eyebrow. Etc. Sorry, thought that was more common than it is.

Even Americans have -120 - 0 - +120 volts. So you have 240V. I believe they're available for "dryer circuits" etc.

Right. It's called "split phase," and it's the standard in the US, Canada, etc. L1 and L2 are 180 degrees out of phase, with 240V between them, and 120V relative to a (nominally) 0V neutral. A standard 120V outlet is one of the two hots and the neutral, usually rated for 15A, but you can find 20A ones too (they have a "T" on one side, because there are 20A plugs that won't connect with a regular outlet. The "dryer plug" outlets (typically a 14-50 connector) are 50A, L1/N/L2, so you can pull 120V off each side to neutral, or 240V between them. There are also some 240V plugs that don't carry the neutral through - just L1/L2.

If you're running your own circuits to a compute area, it's just as easy to run 240V as to run 120V, though most high power runs will take a neutral through as well, so you have whatever you need at the end.

Or if you have one of those double 120V outlets, you'll probably find one outlet is -120V and one is +120V, so you can change that outlet to a single 240V one by using the two hots.

A two plug 120V outlet will typically be just one phase, though I believe they can be split and wired separately if you really want. And, yes, the "two out of phase 120V to 240V" adapters are common enough - a lot of people use them for higher power EV charging when at a weekend cabin or something.

In any case, this only matters if you're trying to optimize power costs for compute. If you don't care, then just get whatever's cheap. I run a lot of used power supplies because I don't care about the efficiency there.

1. Where I live, less than 3km from the two Uni campuses (that had multi-terabit bandwidth 12 years ago when I quit there) in this metro area, Gbit Fiber is "not available" to my home.

In the UK I'm lucky to have governments intent on modernising the communications structure. The telecoms provider I believe is forced to meet certain deadlines, like x% of homes with Gbit fibre by a certain year.

I might be able to double my upload speed on ADSL at about the same price I'm paying now for 568 kbytes/sec upload.

Oy vey! I remember that speed over a decade ago. So slow by the time it downloads you forget why you downloaded it.

Paying also for coax cable would bring my total upload bandwidth to 2Mbyte or 20mbit for an extra 80 USD/month.

Ouch. Currently I pay $35 (I'm in the UK but converting to US dollars) a month for 32 down 7 up. Soon 1000 down 220 up for only an extra $12. There's 4G I can get for the same price and a similar speed. Soon to be 5G at who knows what speed.

2. Disk space is to totally cheap here now. When the upload fail on CPDN happened all I needed to do was to re-assign some some spare less-than-
terabyte free space. No problem, no cost

I stopped using rust spinners, far too slow for some projects like LHC. NVME on the boards that take it, otherwise SSD. I know there are adapters, but it uses up a slot I could be connecting graphics cards to. One board only has a single slot!!

3. RAM capacity. I use AMD Ryzen 7 and 9.. They use DDR4 ECC UDIMMS @ 3200. The price of those has dropped fast as DDR5 is newest thing. 64GB 3200 UDIMMS (the least possible RAM for the current oifs models and CPUs with at least 8 cores using only 5 out of 8.) now way less than 300 USD at NEMIX.com.

Did you say $300 for 64GB? It's $170 here.

I'll buy another 64G soon, before they run out of stock.Memory speed has little effect on oifs jobs so far in my experience.

I find dual channel RAM makes only a slight difference on some things but not many. Hence I just stick in a 32GB stick, then another later. Better than some day having to remove and waste a smaller one to upgrade. As for speed, the price doesn't seem much different, so I just buy the fastest the CPU supports. I don't overclock, asking for stability problems and wasted time screwing up workunits.

Memory space can, and has, wasted some workunits for me. Like when I allowed 5 oifs to run on a AMD 5900X with only 32G ECC UDIMMS. And no swap space. The dreaded OOM-killer. Not good.

It's amazing how computers fall over when they run out of RAM. Windows just seizes. And the ridiculous thing is they don't give priority to the task manager, so you can't kill what stole all the memory and have to shut the power off.

So, for me here, Disk and RAM getting cheaper, internet bandwidth upload unavailable, CPUs relatively cheap. I'm gonna ask my kid who lives on the edge of a barrio, who I think said that they have gigabit fiber up and down.
Only in the USA :(

Are you line of sight of someone with gigabit? You could get a ground to ground dish between you. My last place of work did that, we had 6 places around the town, and from the roof they could all see the central office, so they got the broadband and the rest of us had dishes. Which was fun climbing up on the roof to tighten the bracket after a strong wind. Yes boss, of course I have ladder training ;-) Look I fixed the internet, are you complaining?

Again... I don't understand your point here. If I decide I want 0AWG, I buy 0AWG from a supplier. If I am fine with 4AWG, I buy 4AWG. These are technical descriptions of wire.

Which are not well thought out. 4AWG is supposed to pass a certain current, but at that current it gets too warm and drops voltage. So from this company their wire is performing like 4AWG should.

If I ordered 4AWG and got 0AWG instead, I'd send it back as the wrong product, because it wouldn't fit in my cable terminators (typically).

Connections typically take all sorts of sizes. Especially my setup with hose clips! You can always take off some of the strands to fit it into a smaller connector (which I've done for the 83A power supplies which have connectors too small to get 83A wire into, nevermind 400A).

If you need to keep the temperature rise on a run down, you spec the proper cable for it, though even the cheap stuff is rated to 60C insulation temps, with most stuff being rated to 90C.

Nothing should be more than body temperature, even if the cable is fine, what's it running against or under? I see whoever wired this house did overkill like I do. The 30A electric shower has a 60A cable. The 30A socket circuits use 50A cable.

Confused look. Raised eyebrow. Etc. Sorry, thought that was more common than it is.

Ah, it looked like one eye bigger than the other. It also looks exactly like the "one side is heavier than the other you are overloading your UPS" symbol on my UPS.

Right. It's called "split phase," and it's the standard in the US, Canada, etc. L1 and L2 are 180 degrees out of phase, with 240V between them, and 120V relative to a (nominally) 0V neutral. A standard 120V outlet is one of the two hots and the neutral, usually rated for 15A, but you can find 20A ones too (they have a "T" on one side, because there are 20A plugs that won't connect with a regular outlet. The "dryer plug" outlets (typically a 14-50 connector) are 50A, L1/N/L2, so you can pull 120V off each side to neutral, or 240V between them. There are also some 240V plugs that don't carry the neutral through - just L1/L2.

Did you say 50A at 240V? That is a big dryer. Ours are 12A. I know Americans are bigger and wear larger clothes but still.

If you're running your own circuits to a compute area, it's just as easy to run 240V as to run 120V, though most high power runs will take a neutral through as well, so you have whatever you need at the end.

Yes but my point is even if you happen to have the normal 120V outlets in a room you stick computers in, you can just change the outlet and get 240V. I thought they were all doubles with one of them being +120 and the other -120.

A two plug 120V outlet will typically be just one phase, though I believe they can be split and wired separately if you really want. And, yes, the "two out of phase 120V to 240V" adapters are common enough - a lot of people use them for higher power EV charging when at a weekend cabin or something.

Would you believe in this country I'm supposed to have an EV outlet professionally installed, and notify the power company (like they need to know what I'm using the power for). Needless to say, no, I wire everything myself. And it won't be a petty little one either, I can get 100 amps at 240V here, and the car will receive all of it.

In any case, this only matters if you're trying to optimize power costs for compute. If you don't care, then just get whatever's cheap. I run a lot of used power supplies because I don't care about the efficiency there.

I gave up on cheap (CIT) power supplies because their 12V line is dodgy, often goes down below 11.5V Useless for GPUs, especially old ones on their last legs. I use the cheap PSUs for the motherboards and 83A 12V (adjustable up and down by almost a volt) LED power supplies for the GPUs.

Which are not well thought out. 4AWG is supposed to pass a certain current, but at that current it gets too warm and drops voltage. So from this company their wire is performing like 4AWG should.

Oh ffs. Use whatever you want, then. If you have a specified temperature rise in mind, you can absolutely spec wire for that, and there are various deratings applied to high temperature use under various electrical codes. There's no "certain current" it's supposed to pass, you do the math to figure out what gauge you need to meet your wiring requirements.

Midnite Solar has observed that 12AWG can pass north of 10,000A - if only very briefly, when doing surge suppression on solar installs. It's fine for that purpose, though I wouldn't use it for a 10kA feeder.

You can always take off some of the strands to fit it into a smaller connector (which I've done for the 83A power supplies which have connectors too small to get 83A wire into, nevermind 400A).

Not permitted in any electrical code I've ever read.

Did you say 50A at 240V? That is a big dryer. Ours are 12A. I know Americans are bigger and wear larger clothes but still.

I did. Just because the plug and wiring are rated for it doesn't mean the dryer pulls it. It's the standard "high power 240V with a neutral" plug in the US. I've got one on a solar trailer that can't source anywhere near 50A continuous, but it's still what stuff uses, and it's very easy to break out into a bunch of 120V outlets.

Yes but my point is even if you happen to have the normal 120V outlets in a room you stick computers in, you can just change the outlet and get 240V. I thought they were all doubles with one of them being +120 and the other -120.

I've never seen that in any house I've been in. Believe me, if it was there, I'd make use of it. If there are two plugs on top of each other, it's always (in my experience) a single phase and neutral. I've seen quad boxes wired up with both phases and neutral, but it's rare.

In any case. On topic: Add more RAM. And I guess avoid AMD, that double free thing is being a royal pain on them for some reason, though it's happening on enough different boxes (including cloud systems I know very well are ECC) that I don't believe it's RAM errors, just something in whatever code path AMD chips end up on.

Oh ffs. Use whatever you want, then

I use this because it's the cheapest 4AWG available, and is as good as 0! And they don't lie about the current it will take like most people do. The standards are just plain wrong and very dangerous.

Not permitted in any electrical code I've ever read.

So? And that doesn't make sense anyway, if you use a cable twice as thick but only put half the strands into the connector, you're better off than if you'd used the thinner cable and left all the strands in, since the vast majority of the length is thicker, and a tiny bit is the same! Think, don't blindly follow codes (whatever they are, we don't have such nonsense in the UK). And er... does this magic code include GPU power? I bet it's not in there.

I did. Just because the plug and wiring are rated for it doesn't mean the dryer pulls it. It's the standard "high power 240V with a neutral" plug in the US.

What would you be plugging in which draws 50% of the power you can get for your whole house?

I've got one on a solar trailer that can't source anywhere near 50A continuous, but it's still what stuff uses, and it's very easy to break out into a bunch of 120V outlets.

Er... didn't that break your precious code? You're using a connector which can't handle what it's meant to?

I've never seen that in any house I've been in. Believe me, if it was there, I'd make use of it. If there are two plugs on top of each other, it's always (in my experience) a single phase and neutral. I've seen quad boxes wired up with both phases and neutral, but it's rare.

https://www.thespruce.com/electrical-split-outlet-warnings-and-rules-1152798

In any case. On topic: Add more RAM. And I guess avoid AMD, that double free thing is being a royal pain on them for some reason, though it's happening on enough different boxes (including cloud systems I know very well are ECC) that I don't believe it's RAM errors, just something in whatever code path AMD chips end up on.

What double free thing? And who needs more RAM?

SolarSyonyk wrote:

I guess avoid AMD, that double free thing is being a royal pain on them for some reason, though it's happening on enough different boxes (including cloud systems I know very well are ECC) that I don't believe it's RAM errors, just something in whatever code path AMD chips end up on.

Here is an Intel Broadwell-EP (host 1534812) which has got a bunch of "double free or corruption (out)" too. (In this host's list of oifs_43r3_ps results with error status, look at those which finished on January 12 and took less than 70,000 seconds.)