Epilogue
The darkFlash UPMOST 1250W is a decent-performing PSU, which could be notably better if the ripple at 12V was lower under full load and if the transient response on the same rail was improved. Currently, the 12V rail drops dead low under the increased transient loads that the ATX v3.1 spec requires, and the OEM of this unit should look into this issue and fix it. The tiny platform allows for a super small PCB, but combining the small PCB and the restrictive fan grille leads to sky-high noise output. Clearly, Zhong Yuan Power didn’t pay much attention to the fan speed profile of this platform, which is a mess in all load ranges. If you cannot stand noisy PC parts, this PSU is not for you. Now, if you mostly care about price, this is a decently priced product using good parts, so it will most likely not have any issues in the long run. Surviving all my tests without breaking means a lot regarding reliability. Especially during the protection features evaluation, I push hard the products under test, far beyond their official ratings, to see if they can withstand abuse, besides checking if their protection features are properly set. In this unit, the OCP triggering points on the minor rails are set sky-high, and although it survived my tests, this can be a problem in the long run. There is no need for such high power levels on the minor rails, especially at 3.3V. Lastly, the unit’s 5VSB rail is only rated at 2.5A, while the ATX spec recommends at least 3A, but it can deliver up to 3.9A before its OCP engages.
It is always interesting to test new platforms instead of the typical stuff, and I highly welcome a new OEM to the PSU market, where several big players dominate the field. I have said that many times in the past, but I will repeat it: competition is good for all of us. Hopefully, we will see more platforms from this OEM, Zhong Yuan Power, and improvements in the sections that I highlighted in this review, especially noise output.
Before investing in a new power supply, read my Best ATX v3.x PSUs article to check all alternative PSU offerings. You help me a lot by using my affiliate links, which don’t increase the product’s price. I get a commission from Amazon every time you do it, which can make a difference for me, especially now that I am on my own, working exclusively for my media and not for someone else.
- Delivered full power at 47°C
- ATX v3.0 and PCIe 5.0 ready
- Properly set 12V OCP and OPP triggering points
- Tight load regulation
- Good enough 12V performance (normal loads)
- Long hold-up time
- High APFC converter’s performance
- Low inrush current at 230V
- Low vampire power at 115V
- Alternative Low Power Mode (ALPM) compatible
- Fully modular
- 12+4 pin PCIe connector (600W)
- Compact dimensions (140mm depth)
- Ideal distance between the peripheral connectors (150mm)
- Sky-high set OCP triggering points on the minor rails
- Increased ripple at 12V under full load
- High voltage drops at 12V in the ATX v3.1 transient response tests
- Mediocre transient response performance on the minor rails (normal loads)
- Both EPS on the same cable can cause trouble
- Lower than 70% efficiency with a 2% load
- Above 0.1W standby power at 230V
Is it just me or could the PSU have performed significantly better in ripple suppression and transient response if they hadn’t gone with such an extremely low amount of secondary caps on the secondary side?
I count 27 caps or which many are fairly small. Other manufacturers like Seasonic are liable to use over 50 caps in that power class.
Yes the form factor is small but they definitely had space for more caps on the breakout board. They cheaped out, which is a pity.
Aris would you review Antec SF850X & Gamemax GX-1050 PRO ?
if they send them to me sure 🙂
UPMOST? XD
It’s nice to see that there is so much optimism and imagination around.
This should lead to improvement.