Customer Reviews

Coolmax M-500B 500W Eps Power Supply with 5 Sata Connectors ATX12V & EPS12V

5 star:		(18)
4 star:		(11)
3 star:		(4)
2 star:		(4)
1 star:		(13)

 

 

I've purchased this CoolMax M-500 B power supply at Amazon.com and that this unit works okay on my computer most of the time, although the power rating is somewhat inflated. As compared to a high quality expensive unit, this one is more like a unit rated at 300 W to 350W. Also because it uses a much less sophisticated voltage regulation being group regulated, the cross regulation between different rails nowhere as good as a much more expensive unit. Being an inexpensive unit, it also does claimed have PFC but it doesn't actually have have any. The specification lists a power factor correction of 99% but the actual unit lacks any power factor correction and has a maximum efficiency of up to 70% at peak output. For one thing it does have is an extremely quiet 120mm fan. Overall, some of the faults I have to say about this power supply is the wires a little on the short side for anything but a micro ATX system. Speaking of the wires, even though it wasn't listed in the specification. It does have a single plug for the floppy drive on one of the wire string that has the four pin Molex. Also this unit claimed to have dual virtual rail for the 12 V, but it is actually a single rail. The metal used in the case is somewhat of a thinner gauge than the more expensive quality units. Fortunately being an inexpensive unit, practically all the wires are of 18gauge construction unlike some of the generic brands that may have thinner 20gauge wires.

I purchased this unit to use on my secondary computer that has the Asrock 775i65G motherboard because I do have a better power supply that doesn't work with this motherboard. That power supply is the Antec Truepower Trio 430 W triple rail power supply. I was taking a chance on the purchase of this power supply hoping it will work with this motherboard. Apparently, it works most of the time but sometimes the computer refused to boot. I've decided to fool around with the bios trying to overclock the computer, and it failed to post or boot even after I cleared the CMOS from that point on no matter how many time I tried. The computer works again as soon as I reinstall the old sparkie power supply. Correction, this problem was caused by the motherboard bios and not this power supply or any adequate power supply. It was resolved after the motherboard bios was updated to version 3.3.

Update October 10, 2009: Because of the boot problem, I had no choice but to reinstall the old 250 W sparkie power supply and keep this as my spare. As soon as I reinstall the old unit, the computer was able to boot. After taking the CoolMax out of the computer, I ran some tests on the power supply and it was okay. I decided that I don't care about the warranty on this unit and opened it to check to see what kind of quality I am getting. What I found was subpar construction inside with no name capacitors and fairly small heatsinks for a 500 W unit. My 250 W sparkle power supply has larger heatsinks and has a much more sophisticated in-line noise filter then this unit. I have seen worse units than this CoolMax when it comes to quality. Also, the soldering job underneath the circuit board this kind of sloppy. Because of this, my advice for anyone who wanted to buy a cheap power supply is perhaps go with Sparkle or FSP Group power supplies. I've took apart several sparkle model power supplies and notice fairly decent sized parts and much better construction than this CoolMax unit. (Note! All sparkle power supplies are manufactured by FSP Group).In most cases,sparkle power supplies are more honest with the power rating then the generic brands. The 350 W sparkle power supply that is also carried here at Amazon.com is actually is slightly more powerful than this CoolMax unit for about the same price.

Warning risk of electrical fire! Do not use the included line cord, but to discard it. If you need a line cord, it's probably best to buy one locally after inspecting it making sure it's 18gauge construction. The included line cord is of very poor quality and it doesn't have the UL certification. When I compared it with a standard line computer line cord, it was much lighter and thinner. The standard UL certified line cord has 18gauge wires minimum as compared to this one with only 26gauge. Prior to discarding this line cord, I've decided to cut it open and found the extremely thin wires inside. In the event of any malfunction or short-circuit, instead of the circuit breaker or fuses tripping or blowing the wires in this cord light up instead. This appears to be a problem with most generic power supply that also includes a line cord set.

I just installed this power supply into a machine to replace an old supply today. Everything seems to be in working order, and the supply is *very* quiet compared to my old one. Running at peak power loads the unit is functioning well.

Two things to note though: 1) There are no small 4-pin hook ups included, which are used to power extra cooling fans (among other low power draws). You can separately buy adapters, or if this is a replacement, you can cannibalize them from the old unit. 2) The PCI-E power cord for a graphics card was pretty short. On my Abit ATX motherboard with an NVidia 8800, the cord is stretched tight to reach the socket. Some case configurations may need an extension for the cord to reach all the way.

First off, the description of the power supply was very misleading. I am not a tech by any means, but when it said it has 5 SATA connectors, I wasn't sure if it had the standard IDE connectors (the 4 pin periphials) as well. I bought it on faith that no power supply could just have SATA and the gambit paid off. It has plenty of SATA and 4 pins (five of each).

I would like to say that a power supply is just a power supply, but the one I was replacing was a Dynex 500 watt power supply. When I first got it at Best Buy I thought this was awesome, a 500 watt power supply! Two months later I had to replace it because it burnt out. A year later and that one burnt out too...this time with sparks flaring out of the back of my rig. Of course I couldn't find a power supply locally that was 500 watts, so I turned to trusty Amazon.

Right as soon as I opened it you could tell the quality difference. The old one I had could have been manufactured in the 1970's it looked so old with the way they had all the cables in there. The Coolmax had a better casing, and everything inside is neatly tucked. Not one loose cable. I've had it running for a month now, and will update if it needs any, but it's not looking like it.

I has been bought this power supply reference for more than one year and the quality is great, personally I try a nvidia geforce 9800GTX and ATI HD4850 with no problem, even using 3 hard disks , Intel E8400 OC @4ghz and like a 3 fans.

I think this is the best performance/price powersupply for single GPU videocards.

Power supply burned out in 1.5 months of use. Amazon will not take it back because it passed their 30 days period so I'm working with the manufacturer(1 year warranty) to get it replaced. Buy at your own risk.

I have had this in 3 days and I can't even hear it and it sure has the power I need for my system which is a HP Pavilion p6110f Has a lot of memory and it needed more power. This one was better than the antec 550watt I tried, more power and quieter. It has only been 3 days so we will see if anything changes I will post it but for now it is a kick butt quiet power supply.

it works great, its silent, but would not recommend it to anyone building a budget gaming pc due to heat issues. if your building a basic gaming pc id recommend a different brand like corsair even if it costs a little more.

I bought this to replace the power supply in my old PC, works ok, but I don't use anything under 700w in mine and they gotta have 2 PCIe connectors. I'm a little skeptical about a 500w PS with 4 peripheral AND 4 SATA and a PCIe connector. More convenient ? hmmm just more wires laying around inside the case if you aren't using them and I'm not going to be using 4 peripheral AND 4 SATA are you ?

Any way, I knew what I was getting anyway because I got it cheap. For those of you buying things from AMAZON, they are notorious for not having very good descriptions of products, so instead of getting burned or "taking a chance" LOOK the product up on other sites to not only get a better description but also better images and even opinions.
I continue to see people ordering things on AMAZON, not just PC parts, and having them say the description didn't say this or that. LOOK IT UP AT ANOTHER SITE...LOL

The power cables that plugin into the motherboard are too short if you have a large case with the PSU mounted at the bottom of the case.

I bought two of these. One for a new build and one as a spare. When I put the system together, I got the green LED on the mobo but nothing else.
After testing out individual components, I was about to return the mobo but decided to try the other power supply just for the heck of it. It booted right up.
They weren't any cheaper than my Ultra LS power supplies and those work great! Guess I should have stuck with them.
I still can't believe that a brand new power supply arrived DOA. Pathetic.