Buying a PC Power Supply in the UK, January 2012

In the process of building my first desktop PC in about 4 years, I’ve come to realise that I no longer know anything about PC hardware. At one stage I considered myself, perhaps incorrectly, to be fairly knowledgeable about the subject of PC power supplies, even writing a PSU guide for a forum I used to frequent. Most of that guide is now irrelevant but looking back it wasn’t terrible advice for a newbie looking to buy a PSU at that time.

The PC I’m building is what I would call a mid-range gaming-capable PC. I will mostly use it for internet/email, photo editing and the odd bit of gaming:

  • Intel Core i5 2500 (not the “K” version because I would rather have Vt-d than an unlocked multiplier)
  • Asus P8Z68-M PRO
  • Corsair Vengeance 16GB (4x4GB) DDR3 ram
  • Sapphire AMD 6850 1GB
  • Seagate 7200.12 1TB HDD
  • OCZ Agility 3 120GB SSD
  • Misc – DVDRW, card reader

All in a Fractal Define Mini micro-ATX case.

After spending several hours researching power supplies I decided to document some of what I’ve learned.

A minefield

PCs are capable of drawing much more power in 2012 than they were in 2004 when I wrote the guide, but the power draw of the average PC hasn’t changed a huge amount. And unlike in 2004, all PSUs available today meet the more stringent ATX v2.x specifications. So one would hope that exploding PSUs are less common.

The reason I post that link though is that the second person in that thread says though:

Corsair has a good reputation overall though so you will probably be better off that [sic] you were”

Corsair’s reputation, as best I can tell, was built on some high-end models and an excellent budget power supply, the 400CX. That PSU was manufactured by Seasonic, but it was unfortunately replaced with the 430CX, and the result was not so spectacular.

The situation was similar in 2006 with OCZ. In the PSU guide above I wrote:

Excellent power supplies, but prohibitively expensive. Only recommended for ultra-high end buyers, wasted on anything mid-range.

At the time, OCZ were of course new to the market, and started out with only a handful of expensive high-end offerings aimed at overclockers. Today you can get OCZ power supplies from £40 to £200, and the variation in quality is obviously huge.

Of course OCZ don’t manufacture power supplies and they never did. They outsource production to a third parties, and these third parties vary greatly on the quality.

Brand, what brand?

The Corsair CX400 was manufactured by Seasonic, the CX430 is manufactured by CWT. What can we take from this? Basically, the brand on the box doesn’t matter, but the manufacturer and internal design does.

This creates a problem for the wants-to-be-informed PSU buyer, as we effectively have a layer of abstraction to dig through to evaluate a given power supply. OCZ and Corsair don’t advertise who the original manufacturer was on the box.

Based on brand reputation I’m likely to buy a Corsair CX430, but then I’d be purchasing a CWT power supply based on reputation earned by a Seasonic unit. Totally ridiculous, but most purchasers would have no idea.

One way to avoid this might be to avoid the retail brands and buy from manufacturers that manufacture power supplies themselves, such as Seasonic, Enermax and Superflower. The downside is that these companies have inferior distribution to brands such as OCZ, Thermaltake and Corsair, because the latter group sell a variety of products and have much larger networks of distributors.

Another problem is when OEM brands outsource themselves. The Enermax NAXN 550W for example uses a cheap CWT design (source), making it an Enermax power supply in name only. Previously I would have recommended Enermax as a brand generally, however this is no longer the case!

Seasonic and Superflower remain the only two brands I can think of that produce only good-quality retail units.

Options I looked at

The prices I’m taking from Yoyotech, as that’s the store I’ll be purchasing from. I haven’t used them before, but the prices are reasonable and they have the option of picking up at their store in London.

The price range I’m looking at is up to £60, and few of the power supplies below are modular. While this would be a desirable feature in the MATX case, sacrifices do have to be made at this price point and I would much rather have quality internals than detachable cables.

Brand Model 80-Plus Certification Price Original Manufacturer
Corsair 430CX V2 80+ £36.83 CWT
Enermax NAXN 550W 80+ £50.20 CWT
OCZ ZS 550W 80+ bronze £48.36 Sirtec
OCZ Modstream 500MXSP 80+ £51.06 Sirtec
OCZ Fatal1ty 550W 80+ £54.23 Sirtec
Antec HCG-550 Plus 80+ bronze £57.30 Seasonic

Notes and comments

  • The CWT-manufactured CX430V2 in this table isn’t the same as the CX430 mentioned above. It is apparently a better power supply than the original CX430, but is still a CWT unit and still pales in comparison to the CX400.
  • The Antec HCG was a late addition to this list and one I hadn’t even considered before I started writing this blog post. Why? Well, the G stands for Gamer. It does seem that Antec has spent a fair amount on marketing this PSU as reviews are plentiful on the web.
  • The Enermax NAXN got struck off the list straight away. It’s a cheap PSU in premium-branded clothing, and you’d be better off purchasing the 430CX V2 in my opinion.
  • The OCZ ZS550W was the front runner before I read up on the HCG-550. It received a good review at, but I have a strong preference for Seasonic over Sirtec.
  • When you compare the Enermax NAXN and the Antec HCG it’s a wonder they sell for a comparable price. The internals are in a completely different class.

Wrap Up

Several hours of research have resulted in me deciding to buy the Antec HCG-550 Plus. It’s exactly what I’m looking for – quality components and circuit design in a no-frills package. Sold.

Bit-tech did note that the 12V rail on their sample dropped below ATX spec under full load. This is a concern but since I won’t be pushing it very hard I’ll take the lower ripple currents thankyouverymuch.

The CX430V2 is good value at only £36, but you are getting what you pay for. From what I can gather, it’s the kind of design you’d find included with a good-quality case. I feel that the HCG, while more expensive, punches above its weight.

Recommended Reading

  • is a bunch of Spanish engineering students who evaluate PSUs down to the component level. It’s well worth reading their conclusions and the PSU database is useful.
  • are a UK based site and have recently done a PSU roundup
  • Anandtech review of the HCG-550 would be worth reading if you’re also considering that model.
  • Johnny Guru’s review of the CX430W V2 is also well worth reading if the Antec is a bit expensive for your tastes

4 thoughts on “Buying a PC Power Supply in the UK, January 2012

  1. Adam

    Tapping my foot, its time to surrender to Steve Job and get a Mac Alex! Nice Pics on FaceBook, What sort of camera do you use more to the point what lens are you using?

    1. Alex Post author

      Hey Adam! Would consider a Macbook but not looking for another laptop here!
      Using a Canon 40D, have a few lenses but mostly use an EF-S 10-22mm.

  2. vt-d query


    I realize this is a somewhat old post, but can you confirm that the Asus P8Z68-M PRO actually supports vt-d? I’ve been looking for an unequivocal confirmation of this support for over an hour now and the best I managed to find were some dubious “it should”, “I’m not sure it does”, “it might not”, etc. TIA

    1. Alex Post author

      Can’t confirm sorry as I have an i5 3750K which itself does not support VT-d, but I can’t see any reason why it wouldn’t.


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