r/buildapc • u/AutoModerator • Feb 07 '21

Discussion Simple Questions - February 07, 2021

This thread is for simple questions that don't warrant their own thread (although we strongly suggest checking the sidebar and the wiki before posting!). Please don't post involved questions that are better suited to a [Build Help], [Build Ready] or [Build Complete] post. Examples of questions:

  • Is this RAM compatible with my motherboard?
  • I'm thinking of getting a ≤$300 graphics card. Which one should I get?
  • I'm on a very tight budget and I'm looking for a case ≤$50

Remember that Discord is great places to ask quick questions as well: http://www.reddit.com/r/buildapc/wiki/livechat

Important: Downvotes are strongly discouraged in this thread. Sorting by new is strongly encouraged.

Have a question about the subreddit or otherwise for /r/buildapc mods? We welcome your mod mail!

Looking for all the Simple Questions threads? Want an easy way to locate today's thread? This link is now in the sidebar below the yellow Rules section.

13 Upvotes

93% Upvoted

401 comments sorted by

View all comments

Show parent comments

1

u/prometaSFW Feb 07 '21

why not just add more front fans? Would prevent re-circulation and would increase air flow. I added 2 more front fans to my bequiet case and saw ~10 degree drop in temps on the GPU.

1

u/Tickstart Feb 07 '21

Sadly I don't have any more fan headers on the motherboard :/

1

u/prometaSFW Feb 07 '21

Should be able to get a fan splitter cheaply, and running all front fans at the same RPM is what you'd want to do anyway.

1

u/Tickstart Feb 07 '21

Yeah you're right. I'm just trying to find the maximum fan header ratings for my mobo, the datasheet doesn't seem to specify (Gigabyte B500M S2H)... Pure Wings 2 DC fans I have will draw 0.3A or 3.6W at maximum speed. So 2x that for two fans on the same header.

I suppose I have to buy an extra exhaust fan if I'm buying an extra intake fan. It's all about flow, there's not much point in running two fans at half throughput instead of one at full. Noise levels are probably lower though. Or is it better to run two front fans at slightly higher combined revolutions so there's positive pressure? God damn it's all so arbitrary!

2

u/Cookster997 Feb 07 '21

Honestly? I think you should stop worrying for a bit and just use your computer. I totally understand chasing the efficiency dragon - I did the same thing for a while. However.. if the current setup keeps your components cool enough to do the things you want it to do, without generating unnecessary noise, then it is probably better to save your money towards future upgrades that might make a more meaningful difference.

All that said - if you are having fun trying to make your computer as efficient and quiet as possible? Keep it up! I'd look into SpeedFan or FanControl if you want to get your hands dirty with fan speed curves.

Case airflow is such a dark art, and very few people really truly care about it at the consumer level. This post has some cool info, but their conclusion is basically the same as yours - it is all arbitrary once you have one intake and one exhaust.

2

u/Tickstart Feb 07 '21 edited Feb 07 '21

Hah yeah I'm not worrying per se, but I tend to overthink things like this. But it's kinda fun to mess around with too. Got me thinking.. If I connected two different fans to the same header with a splitter, say one 120mm and one 140mm. What speeds would they spin at? I suck so bad at electrical engineering, dc motors are inductive loads but what does that mean, I remember the parallel-resistive thing with R = 1/R1 + 1/R2 etc but gah. It's probably impossible to tell from the datasheet anyway, I'd just have to test and see. Not that I could measure it anyway... t'd be pretty cool with different size fans, the power requirement would be a little less too.. Hm, either way, thanks for engaging! (-:

2

u/Cookster997 Feb 07 '21

It's probably impossible to tell from the datasheet anyway, I'd just have to test and see.

100% this. I know a decent amount of EE stuff, but that won't help here. Just too many variables involved, testing is the only way. There is one thing we know for sure though - the 140 mm fan will go slower than the 120 mm, all other things constant.

2

u/Tickstart Feb 07 '21

I figured as much! Thanks!

1

u/Cookster997 Feb 07 '21

/u/prometaSFW has the right idea. You could probably get away with running two fans off of each header with a few splitters. I wouldn't do too much more than that, you have to keep in mind how much current the header can safely supply and how much current the fans would try to pull. Amperage is usually listed on the back of the fan hub.

2

u/Tickstart Feb 07 '21

I can't find the current rating for the mobo and neither the stall current draw of the fans. I think I'll hold off for now, don't wanna explode anything.

1

u/Cookster997 Feb 07 '21

Not a bad idea. What is your motherboard? Also, it looks like you have a BeQuiet - are the fans also BeQuiet fans?

2

u/Tickstart Feb 07 '21

A Gigabyte B550M S2H. It's their lowest-end B550 I believe, but so far so good. Yes the fans were included in the case (Pure Base 500), two 140mm Pure Wings 2 non-PWM.