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Zalman ZM750-EBT PSU Review

Zalman's new EBT line consists of four PSUs ranging from 650W to 1kW capacity. Today, we're testing the ZM750-EBT, which, thanks to a low price, achieves a good value score. But how does it fare in terms of absolute performance?

Our Verdict

Zalman's ZM750-EBT is sold at a fair price and is backed up by a long warranty, however with a few more dollars you can find much better performing PSUs. Sirfa, the PSU's OEM, has some more work to do on this platform in order to fix the performance issues that we spotted.

For

  • Full power at 47 °C (but ripple at 5V and 5VSB was out of range) • Decent build quality • FDB fan • Warranty

Against

  • Ripple • Noisy under stress • Hold-up time • Inrush current • Single EPS connector • Inaccurate PWR_OK signal

Tom's Hardware Verdict

Zalman's ZM750-EBT is sold at a fair price and is backed up by a long warranty, however with a few more dollars you can find much better performing PSUs. Sirfa, the PSU's OEM, has some more work to do on this platform in order to fix the performance issues that we spotted.

Pros

  • +

    Full power at 47 °C (but ripple at 5V and 5VSB was out of range) • Decent build quality • FDB fan • Warranty

Cons

  • -

    Ripple • Noisy under stress • Hold-up time • Inrush current • Single EPS connector • Inaccurate PWR_OK signal

Zalman ZM750-EBT Power Supply Review

Zalman isn't a particularly active company in the PSU market, so it was a nice surprise to see a fresh offering from the company. Zalman's EBT series has four power supplies with capacities ranging from 650W to 1kW. The two smaller models feature semi-modular cabling and are based on Sirfa's HPM platform, while the 850W and 1kW units are fully modular and utilize the Sirfa HPJ platform. Sirfa is an OEM with lots of experience in the lower-end and mid-range categories, so it's a decent choice for the Zalman's EBT line, which targets budget-oriented folks.

All EBT models are 80 Plus Gold-certified and have a single +12V rail. A few years ago, there was a great debate as to whether multiple +12V rails or a single one was better; given the number of single-rail PSUs out there, you can guess the winner. Of course, that doesn't mean PSUs with multiple +12V rails are bad. On the contrary, they offer increased safety. However, you have to properly assign rails to cables and connectors to avoid triggering over-current protection. As a result, we've become accustomed to power supplies with a single +12V rail landing in our lab.

In this review, we're evaluating Zalman's 750W ZM750-EBT. This wattage category is among the toughest, since it includes many capable contenders that are priced aggressively. The ZM750-EBT will have to register a high performance-per-dollar score if it wants to stand out.

We admit that we prefer fully modular PSUs over semi-modular or non-modular ones. However, the first thing that a manufacturer usually leaves out in an effort to lower production costs is modular cables. This PSU has three fixed cables that most PCs need anyway, along with six modular ones. At the time of writing, we found this power supply for less than $100, making it a tempting choice since it undercuts this segment's heavyweights (including Corsair's RM750x and EVGA's SuperNOVA 750 G2 PSUs). If Zalman can get its price even closer to $90, its ZM750-EBT PSU will enjoy a major head-start.

Specifications

Again, this is a Gold-rated PSU. Unfortunately, Zalman says it can only deliver its full power continuously at up to 40 °C, while the ATX spec recommends at least 50 °C. This isn't a high-end platform though, so we probably shouldn't expect it to endure the toughest conditions (admittedly, most PSUs can't handle a full load continuously at 50 °C).

According to Sirfa, this unit comes with all of the necessary protection features, including over-temperature protection (OTP), which is especially crucial for PSUs with lower temperature ratings like this one. A quality Fluid Dynamic Bearing (FDB) fan cools the PSU's internals and there is no semi-passive mode, though that's probably a good thing. A constantly-spinning fan keeps temperatures down under light loads at the expense of greater stress to the cooler which however won't have a problem with this, since it is equipped with a long lasting FDB bearing. Finally, Zalman looks to have high confidence in this design, since recently upgraded its warranty from five years to seven.

Power Specifications

Rail3.3V5V12V5VSB-12V
Max. PowerAmps222262.530.3
Watts120750153.6
Total Max. Power (W)750

The single +12V rail delivers up to 62.5A, so it will easily feed a couple of high-end graphics cards. The minor rails top out at an ample 120W of combined power, while the 5VSB rail has 3A max current output. It should have no problem charging a tablet.

Cables And Connectors

Native Cables
DescriptionCable CountConnector Count (Total)Gauge
ATX connector 20+4 pin (510mm)1118-22AWG
4+4 pin EPS12V (660mm)1118AWG
6+2 pin PCIe (510mm+150mm)1218AWG
Modular Cables
6 pin PCIe (+510mm) 2218AWG
SATA (465mm+150mm+150mm+150mm)2818AWG
4 pin Molex (460mm+150mm+150mm)1318AWG
4 pin Molex (460mm+150mm+150mm) / FDD (+150mm)13 / 118-22AWG

The main ATX cable is a little shorter than we'd like. In our opinion, it should be at least 55cm long. Conversely, the EPS cable has plenty of length; we only wish there were two of them. The PCIe cables are also long enough. But the distance between the connectors (on one cable with two connectors) is a little short, so you'll have to bend them to reach a nearby PCIe slot. Finally, the distance between the SATA and four-pin Molex connectors is great, though in some cases it'd be nice to have less distance between the SATA connectors.

The number of PCIe, SATA and peripheral connectors is adequate for this PSU's category. We'd just like to see that extra EPS lead, or at least a four-pin ATX12V connector. Finally, the wiring is mostly 18-gauge.

The above diagram shows the ZM750-EBT's cables and connectors, along with their length. As mentioned, three of the cables are native, including the essential ATX and EPS connectors. We think that the third fixed cable, used for auxiliary PCIe power, should be modular, since not everyone needs it. Then again, it's probably a safe bet that anyone with a 750W PSU is at least using a mainstream GPU.

Power Distribution

Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.

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Aris Mpitziopoulos
Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.