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New computer + external graphics card?

Posted: Sat Jan 11, 2020 12:49 pm
by Bill Spight
As I have mentioned before, I am planning to get a new computer soon. I am thinking of building it myself, or possibly get some help with that. Anyway, in doing my research I have found that powerful graphics cards run hot, and that the ambient temperature matters. Also, everything heats up inside the box. So, even though nobody who builds their own has suggested it, I have wondered about using the powerful card outside the box, where it would be easier to cool and would not absorb heat from other parts inside the box, nor heat them up.

AFAICT, the main problem with hooking the card up externally (or possibly two cards in the future, but not likely) could create a bottleneck. If nothing else, distance matters, IIUC.

I am planning to develop some models for pedagogical purposes, not for competing with top bots. For instance, models that play different forms of the capture game, a model to play difference games, one to play coupon go, maybe an analyst instead of a player.

Any advice welcome. Many thanks. :)

Re: New computer + external graphics card?

Posted: Sat Jan 11, 2020 1:06 pm
by CarlR
Building a computer is actually quite easy. The hard part is making sure everything is compatible so just run your build through https://uk.pcpartpicker.com/ Connecting it all up is super easy as most connections only fit in one place.

Liquid cooling is probably your best option at keeping everything as cool as possible inside the box.

There is absolutely nothing wrong with having the GPU outside of the case. I've never heard of it causing a bottleneck even with the use of pcie risers. For instance, look up ethereum mining rigs. People run several GPUs outside of the case with the intention of getting maximum performance from each GPU.

Re: New computer + external graphics card?

Posted: Sat Jan 11, 2020 1:25 pm
by Bill Spight
Many thanks, Carl. :)

Re: New computer + external graphics card?

Posted: Sat Jan 11, 2020 2:18 pm
by xela
For what it's worth, my PC is in Australia, in a room without air conditioning, with my GTX 1070 GPU inside the box, and I've never had a problem with it running too hot. You need a big enough box (something sold as a "gaming PC") and at least two fans. My PC case also has a front panel that's designed for easy removal (press, release and lift, almost as easy as opening a cupboard door) if you need better air circulation. Ambient temperatures for me in summer are almost always above 20 centigrade, often in the mid 20s, and sometimes slightly over 30. (That's approx 60-90 fahrenheit for anyone who hasn't gone metric yet.)

I guess you might have issues if your neighbourhood is hotter than mine, or you're using a much more powerful GPU, or you have limited space and need your PC to be inside a smaller case. My previous PC (without GPU) did overheat sometimes on a hot day, but it wasn't in a gaming case, so the ventilation wasn't so good.

Re: New computer + external graphics card?

Posted: Sat Jan 11, 2020 5:31 pm
by Gomoto
I recommend using a good air cooled case.

(They have no problems with the temps of GPUs. I use a Fractal Design Define R6 myself.)

I prefer a good air cooled system over liquid cooling all the time. It is often even more quiet than a liquid cooled system and less disturbing than the noisy pumps of liquid cooled systems.

An external GPU has no advantages for a desktop system.

Re: New computer + external graphics card?

Posted: Sat Jan 11, 2020 6:31 pm
by Bill Spight
Many thanks, xela and Gomoto. :)

From what y'all say and from a little more research, I gather that having two fans, one exhaust and one side panel intake fan should be just fine. :)

I live in a temperate climate, the San Francisco Bay area, but in an old house with poor insulation and no air conditioning and my office/den gets a lot of sun, so that it is not unusual for temperature in the room to reach around 32° C. in a summer afternoon. From what I read the average temperature in the computer would be around 39° C. The GPU itself would be even hotter, OC. This summer I used a fan blowing over a bowl of ice water to cool the room well into the night. This summer maybe I should place the bowl beside the computer. ;)

Re: New computer + external graphics card?

Posted: Sat Jan 11, 2020 7:21 pm
by bernds
Bill Spight wrote:Many thanks, xela and Gomoto. :)

From what y'all say and from a little more research, I gather that having two fans, one exhaust and one side panel intake fan should be just fine. :)

I live in a temperate climate, the San Francisco Bay area, but in an old house with poor insulation and no air conditioning and my office/den gets a lot of sun, so that it is not unusual for temperature in the room to reach around 32° C. in a summer afternoon. From what I read the average temperature in the computer would be around 39° C. The GPU itself would be even hotter, OC. This summer I used a fan blowing over a bowl of ice water to cool the room well into the night. This summer maybe I should place the bowl beside the computer. ;)
Note that the GPU never gets all that hot unless you run a demanding game, or maybe a Go engine. You can simply choose to do neither on the hottest days of the year.

Re: New computer + external graphics card?

Posted: Sat Jan 11, 2020 9:24 pm
by jann
We had some problems with cooling in the past (on heavily used machines), and our standard practice now is to remove one whole side of the box of any new system and replace it with one huge fan. This can be done cheaply and is reasonably effective. (There are theories about airflows in boxes etc, but in practice we found this gives best results.)

Re: New computer + external graphics card?

Posted: Sun Jan 12, 2020 1:19 am
by Bill Spight
bernds wrote:Note that the GPU never gets all that hot unless you run a demanding game, or maybe a Go engine. You can simply choose to do neither on the hottest days of the year.
Many thanks, bernds. :) What with global warming, I may get a small air conditioner, anyway.

Re: New computer + external graphics card?

Posted: Sun Jan 12, 2020 1:21 am
by Bill Spight
jann wrote:We had some problems with cooling in the past (on heavily used machines), and our standard practice now is to remove one whole side of the box of any new system and replace it with one huge fan. This can be done cheaply and is reasonably effective. (There are theories about airflows in boxes etc, but in practice we found this gives best results.)
Many thanks, jann. Is that an intake fan or an exhaust fan?

Re: New computer + external graphics card?

Posted: Sun Jan 12, 2020 3:38 pm
by John Tilley
Bill - I have built my last two PCs - I used a CoolerMaster case for each. I have never used an external card though.

Some advice - get a good size case - its better for air flow and easier for your fingers to assemble. CoolerMaster currently advertise a Mastercase 5 - which supports up to 6 140mm fans and then there are those on your graphics card as well. CoolerMaster cases support water cooling and are aimed at performance PCs - eg gaming. Make sure the fans are advertised as quiet!

Check how many graphics cards your motherboard and case will hold - a small case might be problematic as cards can be quite large and take up 2 slots or possibly more.

Check the total power supply requirements and allow for adding more stuff later - eg another graphics card - there are tools on the web. I have kept my PCs for 5-10 years - so plan ahead and get max memory now - in 2-3 years time your specific memory might not be available.

Good Luck - John

Re: New computer + external graphics card?

Posted: Sun Jan 12, 2020 4:43 pm
by Bill Spight
John Tilley wrote:Bill - I have built my last two PCs - I used a CoolerMaster case for each. I have never used an external card though.

Some advice - get a good size case - its better for air flow and easier for your fingers to assemble. CoolerMaster currently advertise a Mastercase 5 - which supports up to 6 140mm fans and then there are those on your graphics card as well. CoolerMaster cases support water cooling and are aimed at performance PCs - eg gaming. Make sure the fans are advertised as quiet!

Check how many graphics cards your motherboard and case will hold - a small case might be problematic as cards can be quite large and take up 2 slots or possibly more.

Check the total power supply requirements and allow for adding more stuff later - eg another graphics card - there are tools on the web. I have kept my PCs for 5-10 years - so plan ahead and get max memory now - in 2-3 years time your specific memory might not be available.

Good Luck - John
Many thanks, John. Great advice! I'll look for a CoolerMaster case. :D What I have seen recommended is a single blower (exhaust) fan for the GPU, instead of the more usual two or three fans that blow onto the GPU.

Re: New computer + external graphics card?

Posted: Sun Jan 12, 2020 10:59 pm
by jann
Bill Spight wrote:Is that an intake fan or an exhaust fan?
It blows air inside (which then comes out through the normal airflow openings). Our situation were not the same tho, we mostly had problems with mobo overheating, and sometimes with cpu but not gpu.

Re: New computer + external graphics card?

Posted: Mon Jan 13, 2020 1:54 am
by Bill Spight
jann wrote:
Bill Spight wrote:Is that an intake fan or an exhaust fan?
It blows air inside (which then comes out through the normal airflow openings). Our situation were not the same tho, we mostly had problems with mobo overheating, and sometimes with cpu but not gpu.
Ah! Thanks again. :D A large intake fan makes sense.

Re: New computer + external graphics card?

Posted: Mon Jan 13, 2020 1:14 pm
by ez4u
Building your own PC is really a "do it yourself" endeavor. For any given fan in your case, if you want an exhaust fan instead of an intake or vice versa, you just take the screws out, flip the fan over, and put the screws back in. Voila! So a big case with lots of mounts for fans (not necessarily lots of fans to start with) can be a lot of fun to play around with.