Differences between revisions 5 and 6

Contents

Noise levels at different speeds
Heat loads
Fan Control settings
Results
GPU undervolting
Links

Noise levels at different speeds

This is nicely supported by Fan Control now, so it's worth knowing what your RPM and PWM correlation is like.

Pump

This is an EK D5 pump in a FLT120 reservoir.

PWM	RPM	Noise
0%	800	Silent
10%	800	Silent
20%	800	Silent, 20% seems to be the floor for control
25%	1070	Silent
30%	1360	Silent
35%	1640	Some whine
40%	1950	Barely audible even in close proximity
45%	2200	Barely audible even in close proximity
50%	2500	Just noticeable if listening under desk
55%	2770	Somehow quieter than above, same as 45%
60%	3050	Quiet if listening under desk
65%	3330	Pump whine just audible from sitting position above desk
70%	3620	Pump whine higher pitched and more noticeable
75%	3950	Pump whine at maximum noise acceptable in general (quiet) conditions
78%	4075	Weird sweet spot, somehow better than 75% or 80%
85%	4450	Occasional liquid swishing noises
100%	4775	Frequent liquid swishing noises

Pump speed vs flow

Same EK D5 pump in a FLT120 reservoir.

I rebuilt the loop when I changed to the AP201 case, and that changes all the flow values because the loop is different. It's now much less impeded, meaning I get more actual flow for a given pump speed.

Pump PWM	Pump RPM	Flow meter volume	Flow meter tacho	Notes
100%	4775 rpm	3.6 L/min	83 rps	-
85%	4450 rpm	3.3 L/min	76 rps	-
78%	4075 rpm	2.9 L/min	67 rps	-
75%	3950 rpm	2.8 L/min	63 rps	-
65%	3330 rpm	2.3 L/min	52 rps	-
55%	2770 rpm	1.8 L/min	40 rps	-
45%	2200 rpm	1.3 L/min	30 rps	-
35%	1640 rpm	0.7 L/min	16 rps	-
30%	1360 rpm	0.4 L/min	9 rps	-
25%	1140 rpm	0.1 L/min	4 rps	Slowest speed that avoids low-flow alarm

Fans

A pair of Corsair ML140 fans on a Corsair 280mm radiator in the top of the case.

PWM	RPM	Noise
20%	400	Silent
35%	700	Silent
45%	915	Just noticeable if listening under desk
50%	1040	Just noticeable sitting normally above desk
60%	1240	Comfy noise level above desk
70%	1400	Modestly noisy, about as much as you'd want in general (quiet) conditions
80%	1590	Noisy
90%	1730	Very noisy
100%	1875	Too bloody noisy!

Heat loads

Components	Estimated load (Watts approx)
Idle	25
Full CPU	120
Full GPU	250

Fan Control settings

Having gotten a sense for lower and upper bounds that make me happy, I've gone with the following:

	Toe of curve	Idle speed	Shoulder of curve	Load speed
Pump	30°C	1360 rpm	42°C	3600 rpm
Rad fans	30°C	700 rpm	42°C	1500 rpm

This is using the Auto curve, which takes an expected Idle temperature and maximum acceptable Load temperature, and interpolates between them. It'll maintain the Idle speed as long as the liquid temp is below the lower threshold, and ramp up as high as the Load speed as the liquid temp approaches the upper threshold. This ensures that the maximum noise will never be above my comfy levels, even though it means leaving potential cooling performance on the table.

Results

NB: these results are old, they're not for the current system as of 2024-03-22

This is mostly about finding a sweet spot for being quiet at idle, and sufficiently cool under load, without being too noisy.

This is the new loop layout in the Phanteks Evolv Shift Air, after Maru helped out with reworking everything. 280mm radiator with 2x 140mm Corsair maglev fans.

Low speeds

34% fan - 655 rpm
45% pump - 2200 rpm
0.5L/min flow rate - 12rps on the meter

Load	CPU temp	GPU temp	Loop temp	Notes
CPU only	84 C	29 C	28 C	Cinebench R23
GPU only	63 C	54 C	33 C	Furmark
GPU and half-CPU	90 C	59 C	37 C	Furmark and Cinebench limited to half usual threads
GPU and full-CPU	n/a	n/a	n/a	Not tested because the CPU throttles at 90C

Loop speeds are simply too low to get heat out of the chip fast enough, the CPU will lower the boost ceiling to try and stay at 90 degrees.

With some GPU undervolting we get a very healthy improvement in temps:

Load	CPU temp	GPU temp	Loop temp	Notes
GPU only - stock	63 C	54 C	33 C	-
GPU only - undervolted	57 C	48 C	31 C	-

Medium speeds

50% fan - 1000 rpm
60% pump - 3060 rpm
1.0L/min flow rate - 24rps on the meter

Load	CPU temp	GPU temp	Loop temp	Notes
CPU only	82 C	27 C	27 C	Cinebench R23
GPU only	54 C	48 C	31 C	Furmark
GPU and half-CPU	82 C	51 C	33 C	Furmark and Cinebench limited to half usual threads
GPU and full-CPU	90 C	52 C	35 C	Furmark and Cinebench with unlimited threads

This is a fair bump in flow, which suggests that the CPU isn't being cooled effectively when running at fill-tilt, I think. I wish I'd taken note of the CPU speeds, because then the CPU-only and CPU+GPU test cases could be compared.

High speeds

60% fan - 1200 rpm
100% pump - 4800 rpm
2.0L/min flow rate - 47rps on the meter

Load	CPU temp	GPU temp	Loop temp	Notes
CPU only	83 C	-	29 C	Cinebench R23 - 140W
GPU only	55 C	48 C	33 C	Furmark - 280W total power (230W GPU + 50W CPU)
GPU and half-CPU	82 C	50 C	34 C	Furmark and Cinebench limited to half usual threads - 340W power (230W + 110W)
GPU and full-CPU	90 C	-	34 C	Furmark and Cinebench with unlimited threads

Not sure why I don't have GPU temps for all test cases. Very similar to medium flow case, suggesting no benefit from the higher speeds. CPU still hitting it's 90 degree ceiling.

GPU undervolting

Poking at this while running Furmark.

34% fan
45% pump

Stock voltage settings

54 degrees C (loop or GPU core?)
230W GPU power draw
83fps
1068 mV
1950 MHz (GPU core?)

Undervolt applied

47 degrees C (loop or GPU core?)
185W GPU power draw
83fps
950 mV
1950 MHz (GPU core?)

-  ⇤ ← Revision 5 as of 2024-03-22 13:47:14 → 
  Size: 7494
  Editor: furinkan
  Comment: update remaining fan and pump speed/sound observations
+   ← Revision 6 as of 2024-03-22 13:51:23 → ⇥
  Size: 7524
  Editor: furinkan
  Comment: add bottom end of fan control thresholds
-Deletions are marked like this.
+Additions are marked like this.
 Line 53:
+||  20% ||  400 || Silent ||

Useful(?) links

Navigation