When should you add a second pump?

[Caffeine Dealer]

Hey guys!
I'm delving into my 3rd H20 build shortly and have a couple of Q's

Is there a general rule of thumb for when you should add a second pump to a loop?
The plan is....
XSPC RX360 rad > XSPC EX240 rad > XSPC EX240 rad > CPU block > (eventually) GTX 590 GPU block > 2 x 250ml Res.

I currently have 2 pumps... both PMP 450's. 1 adjustable and 1 not adjustable.
Will i need both pumps for a loop of this size? If i were to run just the single adjustable PMP 450, what would i have to remove from the loop for it to work efficiently?

THANKS!

Edit: Is it good practice to run a pump at full speed?

[Hood]

mmm caffeine

Yup, general rule of thumb, second loop/pump over 4-5 blocks depending on how restrictive the blocks are.

Radiators and Res's don't really count as they are very low in term of restriction.

if you use two pumps in the same loop they should be set to the same speed so they don't work against each other, fixed D5's are set to 4

no you don't need 2 pumps for a loop that size.

as long as your temps are fine you don't have to run your pumps at full speed.

[Caffeine Dealer]

Thanks Hood

I'm currently running a single PMP 450 on half speed on my Ivy build but i run out of overclocking potential before i run out of cooling so i was not sure.
In fact... it feels like it never gets hot, even at 4.6 @ 1.4v i never feel any difference in heat being expelled from the rad? lol. I can even run it with the fans turned off if i'm not doing anything taxing.

Anyway.... so a single PMP 450 should be fine with all those rads and a single 590 block huh? Thats good.... now i can sell my spare pump lol.

[miicah]

Uhh ohh...

[Caffeine Dealer]

Originally Posted by miicah

Uhh ohh...

Eh?

[Creekin]

if ur flows below about 2.2L/min its time to split the loop in 2
imho

[leithals]

Originally Posted by Caffeine Dealer

Thanks Hood

I'm currently running a single PMP 450 on half speed on my Ivy build but i run out of overclocking potential before i run out of cooling so i was not sure.
In fact... it feels like it never gets hot, even at 4.6 @ 1.4v i never feel any difference in heat being expelled from the rad? lol. I can even run it with the fans turned off if i'm not doing anything taxing.

Anyway.... so a single PMP 450 should be fine with all those rads and a single 590 block huh? Thats good.... now i can sell my spare pump lol.

my system is just a watercooled CPU at the moment and has been running passively for the last few days. Fans don't kick in until water temp is 25. But i think that's down to it being so darn cold in my PC room...

[Caffeine Dealer]

Thank everyone

[D_W_Y]

i feel if you have 2 pumps in the same closed loop they both need to be EXACTLY the same in terms of flow rate or your creating pressure.

[spud84]

I've got two mpc35x in my loop (CPU, 2xVRM, NB, GPU, 2x240 rad, 1x140 rad). probably overkill....

I added the second pump when i replaced a 120 rad with a 240 and my max temps dropped by about 10-15c (depending on the test), which is more than another 120 worth of rad would give me i reckon, so i'm a believer in dual pumps.

[kazen]

WHO THE FUCK RUNS A PUMP UNDERVOLTED?

[spud84]

Originally Posted by kazen

WHO THE FUCK RUNS A PUMP UNDERVOLTED?

huh?

[Huggy_Bear64]

Originally Posted by kazen

WHO THE FUCK RUNS A PUMP UNDERVOLTED?

I don't see how this is related to the thread.
Or anything else... Ever...

[Creekin]

Originally Posted by spud84

when i replaced a 120 rad with a 240 and my max temps dropped by about 10-15c (depending on the test), which is more than another 120 worth of rad would give me i reckon,

No.

[spud84]

Originally Posted by Creekin

No.

No? What do you mean, that a 120 would drop 10-15 off your loop? well when i added the 120 to the loop that had a 140 and a 240 the tep drop was under 5c so i don't see 120s as being huge performers when put in a loop with plenty of rad already.

The reason why i changed the 120 to a 240 is i punctured the 120 so it needed replacing so i though i may as well upgrade it.