Dell H750P-00 Power Supply Review

Contents

Load Testing

Test 1 (115.0W Load – Cold)

Rail	Load	Voltage	Ripple
12V1	2.38A	11.91V	10.0mV
12V2	2.38A	11.88V	7.8mV
12V3	0A	11.90V	7.8mV
12V4	0A	11.90V	7.0mV
5V	5.02A	5.02V	14.8mV
3.3V	10.03A	3.31V	12.8mV
−12V	0A	−11.98V	4.6mV
5Vsb	0A	4.95V	10mV
AC Power	143.0W
Efficiency	80.42%
Power Factor	0.82

Test 2 (199.59W Load – Cold)

Rail	Load	Voltage	Ripple
12V1	2.38A	11.91V	10.6mV
12V2	2.38A	11.88V	8.4mV
12V3	4.74A	11.85V	8.2mV
12V4	2.38A	11.90V	7.2mV
5V	5.03A	5.03V	8.6mV
3.3V	10.03A	3.31V	12.0mV
−12V	0.1A	−11.99V	5.4mV
5Vsb	0.98A	4.88V	11.6mV
AC Power	242.1W
Efficiency	82.44%
Power Factor	0.91

Test 3 (255.75W Load – Cold)

Rail	Load	Voltage	Ripple
12V1	4.76A	11.9V	12.0mV
12V2	4.74A	11.85V	9.2mV
12V3	4.76A	11.89V	8.4mV
12V4	2.37A	11.85V	7.8mV
5V	5.03A	5.03V	14.2mV
3.3V	10.0A	3.3V	12.8mV
−12V	0.1A	−11.99V	5.8mV
5Vsb	0.98A	4.88V	12.8mV
AC Power	302.6W
Efficiency	84.52%
Power Factor	0.94

Test 4 (308.26W Load – Cold)

Rail	Load	Voltage	Ripple
12V1	4.76A	11.89V	12.8mV
12V2	4.74A	11.84V	9.8mV
12V3	4.75A	11.88V	8.8mV
12V4	4.73A	11.83V	7.6mV
5V	10.04A	5.02V	14.8mV
3.3V	9.97A	3.29V	13.2mV
−12V	0.1A	−12.01V	5.8mV
5Vsb	0.97A	4.86V	13.4mV
AC Power	362.1W
Efficiency	85.13%
Power Factor	0.96

Test 5 (362.76W Load – Cold)

Rail	Load	Voltage	Ripple
12V1	4.76A	11.89V	13.8mV
12V2	4.74A	11.84V	10.6mV
12V3	7.1A	11.83V	9.4mV
12V4	7.1A	11.83V	8.8mV
5V	9.97A	3.29V	14.8mV
3.3V	10.04A	5.02V	13.2mV
−12V	0.1A	−12.02V	6.0mV
5Vsb	0.97A	4.87V	14.0mV
AC Power	422.8W
Efficiency	86.04%
Power Factor	0.97

Test 6 (419.51W Load – Warm)

Rail	Load	Voltage	Ripple
12V1	7.13A	11.89V	14.0mV
12V2	7.09A	11.82V	12.0mV
12V3	7.09A	11.82V	10.8mV
12V4	7.09A	11.82V	9.2mV
5V	10.02A	5.01V	11.6mV
3.3V	10.0A	3.3V	13.8mV
−12V	0.1A	−12.02V	6.4mV
5Vsb	0.97A	4.86V	15.6mV
AC Power	483.7W
Efficiency	86.73%
Power Factor	0.97

Test 7 (475.59W Load – Warm)

Rail	Load	Voltage	Ripple
12V1	7.13A	11.89V	17.4mV
12V2	7.09A	11.82V	13.2mV
12V3	9.46A	11.82V	12.0mV
12V4	9.46A	11.82V	10.8mV
5V	10.04A	5.02V	16.0mV
3.3V	10.0A	3.3V	13.4mV
−12V	0.1A	−12.03V	6.6mV
5Vsb	0.97A	4.86V	16.2mV
AC Power	545.4W
Efficiency	87.20%
Power Factor	0.98

Test 8 (530.29W Load – Warm)

Rail	Load	Voltage	Ripple
12V1	9.49A	11.86V	19.0mV
12V2	9.43A	11.79V	14.8mV
12V3	9.45A	11.81V	13.0mV
12V4	9.45A	11.81V	12.0mV
5V	10.04A	5.04V	16.6mV
3.3V	10.0A	3.3V	13.8mV
−12V	0.1A	−12.03V	7.2mV
5Vsb	0.97A	4.86V	17.2mV
AC Power	608.4W
Efficiency	87.16%
Power Factor	0.96

Test 9 (585.9W Load – Warm)

Rail	Load	Voltage	Ripple
12V1	9.49A	11.86V	20.4mV
12V2	9.42A	11.78V	16.8mV
12V3	11.81A	11.81V	14.6mV
12V4	11.81A	11.81V	13.4mV
5V	10.04A	5.02V	17.0mV
3.3V	10.0A	3.3V	14.0mV
−12V	0.1A	−12.04V	8.0mV
5Vsb	0.97A	4.86V	17.4mV
AC Power	673.2W
Efficiency	87.03%
Power Factor	0.96

Test 10 (638.48W Load – Warm)

Rail	Load	Voltage	Ripple
12V1	11.81A	11.81V	21.8mV
12V2	11.75A	11.75V	18.4mV
12V3	11.80A	11.80V	14.8mV
12V4	11.76A	11.76V	15.4mV
5V	10.04A	5.02V	17.4mV
3.3V	10.0A	3.3V	13.6mV
−12V	0.1A	−12.04V	7.2mV
5Vsb	0.97A	4.84V	17.6mV
AC Power	733.3W
Efficiency	87.07%
Power Factor	0.96

Test 11 (691.9W Load – Warm)

Rail	Load	Voltage	Ripple
12V1	14.15A	11.79V	23.2mV
12V2	14.06A	11.72V	20.0mV
12V3	11.79A	11.79V	16.0mV
12V4	11.79A	11.75V	17.2mV
5V	10.02A	5.01V	16.6mV
3.3V	10.0A	3.3V	14.0mV
−12V	0.1A	−12.04V	7.4mV
5Vsb	0.97A	4.84V	17.2mV
AC Power	797.5W
Efficiency	86.76%
Power Factor	0.98

Test 12 (746.8W Load – Warm)

Rail	Load	Voltage	Ripple
12V1	16.49A	11.78V	24.6mV
12V2	16.37A	11.69V	21.2mV
12V3	11.79A	11.79V	17.4mV
12V4	11.79A	11.79V	18.2mV
5V	10.02A	5.01V	17.4mV
3.3V	10.0A	3.3V	13.4mV
−12V	0.1A	−12.04V	7.6mV
5Vsb	0.97A	4.84V	16.4mV
AC Power	858.4W
Efficiency	87.00%
Power Factor	0.96

Overload Test (906.5W Load – Hot)

Rail	Load	Voltage	Ripple
12V1	16.44A	11.74V	29.6mV
12V2	18.64A	11.65V	25.8mV
12V3	11.76A	11.76V	21.2mV
12V4	11.75A	11.75V	21.8mV
5V	24.9A	4.98V	19.8mV
3.3V	29.55A	3.25V	14.6mV
−12V	0.1A	−12.08V	8.2mV
5Vsb	0.96A	4.81V	17.8mV
AC Power	1041W
Efficiency	87.08%
Power Factor	0.97

This power supply passed all of our tests with flying colours. While the 12V rails were slightly on the low side, they were still within 3% of their nominal values at all times. The 5V, 3.3V and −12V rails hardly budged, and stayed very close to their nominal values. The 5vsb rail was the worst performer, dropping to 4.84V when the PSU was loaded above 600W, but the minimum is 4.75V, and it was still above that. What really impressed me, though, was the ripple suppression. It was below 25mV on the 12V rails, and below 20mV on the other rails at all times. It doesn’t get much better than that. The power supply was also efficient, managing 87.2% efficiency in test 7. I was able to load it up to just over 900W, with the voltages and ripple still in spec and the efficiency still high. When I asked for more, the power supply shut down, so its protections were present and working. The only real disappointment was that there was a very noticeable coil whine when the power supply was running. I could even hear it through the load tester fans. It’s entirely possible that this was just a problem with my unit, and it may not affect all similar power supplies.