About 2 x GPUs and heat problems

[agent71]

I think you misread my post or my post was unintentially confusing. I don't run the P106-90 mining GPU at 125W. It can't run at that wattage. Max it can run at is 75W and minimum 60W. Dropping to 60W makes little or no difference in the GPU temp but causes huge drops in PPD. Max power it'll do 250K PPD but dropping to 60W brings PPD to 150-175K PPD. A >30% drop in PPD.

The RTX however does benefit from capping the wattage. Drop all the way to 125W and RTX2060 still runs about 1.1M PPD compared with 1.5M at full power.

[HaloJones]

it is strange to me seeing all these posts about being power efficient I spend a lot of time and money maximising ppd output and prefer to not look at my power bill

[Neil-B]

I have to admit I don't worry about efficiency either - might have something to do with the 12000 BTU air conditioner I have in my office/server room - without it I might well be looking to be power efficient and minimise the heat generation whilst folding as I would quickly overheat ... tbh without the air conditioner I'd probably also invest in a single decent GPU and stop folding on all my current kit.

[agent71]

it is strange to me seeing all these posts about being power efficient I spend a lot of time and money maximising ppd output and prefer to not look at my power bill

A fair point! I've bought GPUs solely for folding so would be ironic to then be concerned about power costs. I reduce wattage because its too hot or noisy in the office and I just cannot find watercooling for the 2060 I have. Otherwise I'd grab another and water cool them both.

[HaloJones]

it is strange to me seeing all these posts about being power efficient I spend a lot of time and money maximising ppd output and prefer to not look at my power bill

A fair point! I've bought GPUs solely for folding so would be ironic to then be concerned about power costs. I reduce wattage because its too hot or noisey in the office and I just cannot find watercooling for the 2060 I have. Otherwise I'd grab another and water cool them both.

Have you looked at the NZXT G12 and an AIO for your 2060? I do that for one of my 1070s and it's the coolest card I have! even over my full-cover blocked cards

[agent71]

Have you looked at the NZXT G12 and an AIO for your 2060? I do that for one of my 1070s and it's the coolest card I have! even over my full-cover blocked cards

I have although I saw some mixed reviews that put me off at the time although I can't actually recall the issues! What size radiator are you running it with and, case placement issues aside, do you see any problems with running 2 x 2060 each cooled by their own G12 and rad?

I'm tempted to switch CPU cooling to air or even move the 120mm rad to the rear. That would allow me up to a 240 rad on top and a 360 in front.

Forget that.... Just found the issue on NZXT site.
https://www.nzxt.com/products/kraken-g12-white

Code: Select all

Known Incompatibility - Graphics Cards Nvidia GeForce RTX 2060

[MeeLee]

For me, efficiency and cost go hand in hand.
You want to maximize PPD? Instead of trying to overclock GPUs, you'd be able to get more points by just lowering the wattage on all GPUs, and stick another GPU in the PC.

While this makes little sense for GTX GPUs, or systems with only 1 GPU;
once you start with multi RTX, Titans RTX, or Quadro RTX GPU systems, you'll hit the limits of the breaker quite quickly.
That's when capping power becomes a real issue; not only for heat concerns, but also electric cost.
I spend on average the price of one RTX 2060 on electricity per month running 4 servers; constantly playing with hardware for best PPD (or highest performance) per Watt.

I think you misread my post or my post was unintentially confusing. I don't run the P106-90 mining GPU at 125W. It can't run at that wattage. Max it can run at is 75W and minimum 60W. Dropping to 60W makes little or no difference in the GPU temp but causes huge drops in PPD. Max power it'll do 250K PPD but dropping to 60W brings PPD to 150-175K PPD. A >30% drop in PPD.

The RTX however does benefit from capping the wattage. Drop all the way to 125W and RTX2060 still runs about 1.1M PPD compared with 1.5M at full power.

That GPU is closer to a 1050 than a 1060. If they're Chinese branded GPUs, they might have ripped you off, by forcing a 106p bios on a 1050 GPU.
Happened all the time 2-4 years ago.
On my GTX 1050 3GB, I had similar power and PPD values (I hit 300k PPD though), and lowering power to the minimum indeed came with a high PPD penalty.
Those GPUs didn't benefit a lot from capping the power. Instead I used to overclock the crap out of them!
1- They don't really get very hot (in my case, the hottest they became, was like 60C with a 100% fan curve).
2- Those GPUs lower only very little power compared to the overhead of the rest of the PC. If you could lower your electric bill by 15 W on a 200-300W system, it wouldn't make sense losing nearly 100k PPD.

For a 1060, capping the power from 120W to ~85W made a difference. Below 85W (down to 75W) it also suffered too high PPD losses.
I don't have a 1050 anymore, but would advise you to play around with the power curve a bit, and lowering it by 5 or 10% at most from stock.
But on those GPUs, you'll get far better performance, if you can keep the GPUs running in the 50C region (not unattainable on an open cooler, dual fan design)

[gunnarre]

Electricity here in Norway is actually at negative retail prices right now, but utility fees and environmental taxes brings electricity cost up to slightly above 0 per kWh. Thus it's actually more cost effective to fold in the summer than the winter here, since my house is heated with a heat pump. A "folding furnace" is only 100% efficient, while a heat pump is more than 100% efficient at heating a home - and that efficiency only matters in the colder months when electricity prices are high.

Is the radiator fan an intake or exhaust? Conventional wisdom is to have it as an exhaust, but if you want to maximize airflow through the GPU area perhaps setting it as an intake is better, to increase positive pressure? Edit: Alternatively, leaving the radiator fan as an exhaust, but making the rear fan an intake - with dust filters on all intakes, of course. Perhaps put a low profile fan at the bottom of the front too, to make sure less ambient air escapes back out the front.

[agent71]

"free" electricity?!

The 120mm CPU radiator is on the roof and is an exhaust. The two fans at the front are intake. Rear is exhaust and, hidden from view, there is another 120mm fan on the roof as an exhaust.

The case really struggles to pull air and filters are removed from the front and top. That's them on the shelf.

[gunnarre]

Depending on fan speeds, you might have close to a balanced air flow or perhaps even negative pressure. Is the power supply fan taking air from the case or from the outside?

Could you try making the rear fan or both the rear and the back top fan into intakes and leaving the radiator fan as an exhaust? That way, you would maximise the amount of ambient air that flows past the GPUs, through their perforated shields and the perforated area between the glass and the GPUs. There can be a little bit of recirculation effect, but increasing the pressure might make up for that.

"free" electricity?!

Yes, electricity retailers are so competitive that they will offer negative electricity prices to consumers. They're banking on us picking one of their plans, and being too lazy to switch to a new plan when they jack up the prices or add a fixed fee after three months. The electricity price is rarely negative in the bulk market in Norway - though it does happen. In some contries like Germany this happens more often. Edit: Just to be clear, we're still paying the grid company (which owns the power lines) a fixed and per-kWh transfer fee, but some of the electricity retailers (which buy and sell electricity) gives us money for using electricity when electricity prices are negative. For a residential user, that just means that the power company pays the grid company when you use electricity - but some industrial customers - like datacenters - who pay less per-kWh grid fees and no electricity tax might actually earn money from using electricity some days of the year.

[HaloJones]

The case really struggles to pull air and filters are removed from the front and top. That's them on the shelf.

recent case releases are focussing on airflow. The Phanteks P400A and 500A, the Lian Li Lancool 2 Mesh, the Fractal Design Meshify range - all are optimised for airflow where the front panels are mesh instead of solid in front of a mesh.

[Kebast]

Here's what I did. Put 2 GPUs in a case with a large (220mm I think) side fan. Plus all the normal 120mm fans. Top gpu stays around 72C in a 22-23C room, bottom around 68C.

http://i.imgur.com/yFAPyKB.jpg

[Nert]

Here's what I did. Put 2 GPUs in a case with a large (220mm I think) side fan. Plus all the normal 120mm fans. Top gpu stays around 72C in a 22-23C room, bottom around 68C.

I think air from the side (onto the top of the video card) is important. I had a Meshify case with a 1080TI and 1080 in it. I finally had to go with some Noctua industrial type fans in the front to get temps where I wanted them to be .... sounded like a data center machine with those things running . As HaloJones pointed out, the Meshify has lots of mesh areas for air flow. It can draw air from the front and bottom, and the top can be left open for exhaust. The downside for that case is that there isn't much clearance between the top of the card and the side panel. Heat seemed to accumulate at the side panel with two cards. The side panel above the cards was always very warm/hot to the touch. Good to hear that a side panel fan worked for your system.

[DocJonz]

I've been folding with dual GPUs per machine for years. A few tips (for what they are worth);
- Use motherboards that space the PCIe slots so there is always a gap between the two GPUs.
- Use a case where the motherboard is rotated through 90 Deg - heat goes straight up and out.
- If you use GPUs with a TDP of more than about 150W, an additional fan is likely to be required blowing in from the side of the GPUs (I don't 'turn down' the GPUs). As an example, I could put to GTX 1070s in a machine, but two GTX 10180s would need some additional cooling
- Spread the rigs around the house so that it reduces local heat build-up (... the misses permitting!)

I experimented this weekend making use of a motherboard with three PCIe slots which, if three dual slot GPUs were used, they would all be touching and would probably cook themselves to death when under full Folding load. So I built a 'Frankenstein' open case arrangement using a PCIe riser cable to access the middle PCIe slot and move it out of the way. It even booted first time

[MeeLee]

Electricity here in Norway is actually at negative retail prices right now, but utility fees and environmental taxes brings electricity cost up to slightly above 0 per kWh. Thus it's actually more cost effective to fold in the summer than the winter here, since my house is heated with a heat pump. A "folding furnace" is only 100% efficient, while a heat pump is more than 100% efficient at heating a home - and that efficiency only matters in the colder months when electricity prices are high.

Is the radiator fan an intake or exhaust? Conventional wisdom is to have it as an exhaust, but if you want to maximize airflow through the GPU area perhaps setting it as an intake is better, to increase positive pressure? Edit: Alternatively, leaving the radiator fan as an exhaust, but making the rear fan an intake - with dust filters on all intakes, of course. Perhaps put a low profile fan at the bottom of the front too, to make sure less ambient air escapes back out the front.

You're one lucky 'bastard' if I can say so
I wonder if the heat pump can actually feed your PC?

As far as fan suction vs blowing,
Suction is only effective in a small, very spread area.
Blowing allows a more narrow beam (path) of air to cross a section.
Heat sinks benefit most from air blowing on them, as the air gets the most heat away from the GPU, the closer the air can reach the bottom of the cooler.
If the fan sucks air, there's a chance only the top of the cooling fins will receive cooling.
While suction creates sub-pressure, and blowers create a pressure; and pressure introduces heat,
A pressurized region generally also is able to extract more heat.
Kind of like what would happen if you'd replace air with water or oil. The air becomes more dense, and can carry away more heat.

So it's my belief that a case cools better with fans blowing cold air in, rather than sucking hot air out.