650watt or 1050watt power supply for new i7 build


Jan 8, 2010
Noobie here and I'm in the process of building a new music studio PC, most of the parts are ordered but have had a delay with the power supply which was going to be a 650watt Coolermaster one. As I've ordered several parts from one company they have offered me a 1050watt Coolermaster power supply, that they have in stock, as an alternative for just £20 more than the cost of the original 650watt power supply. The full system build is below, but I wanted some opinions on the new power supply option and wether it is over kill or not?

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Music production & graphic design, stricktly no access to the internet!!!

PARTS NOT REQUIRED: keyboard, mouse, monitor, speakers, OS

PREFERRED WEBSITE(S) FOR PARTS: dabs.com & ebuyer.com


2TB Raid SATA hard-drives £215
Asus P6T motherboard £165
M-Audio Delta 66 soundcard £120
ATI 4670 graphics card £55
i7 920 Processor £225
OCZ 6GB DDR3 triple pipe-line memory £140
Coolmaster case £35 - £50




ADDITIONAL COMMENTS: I'll be running it with Windows 7 with the following, Abelton Suit & FL Studio with Rob Papen's Blue & Predator, NI Komplete, Cakewalk Z3ta, Korg Legacy pack, Arturia V Collection, Novation V Station... Plus Adobe design packages.

I wanted a PC that would be a bit of a future proof build, spend a little more now, save a little down the line... So opinions are welcomed :D

Thank you
The general rule of thumb is a high quality 500 to 550 watt power supply with sufficient current (amps) on the +12 volt rail(s) can easily power a system with any single video card made. A high quality 700 to 750 watt power supply with sufficient current (amps) on the +12 volt rail(s) can power a system with two video cards operating in dual mode. There are a few exceptions like the new ATI Radeon HD 5XXX series cards which use less power due to their energy efficiency.

A high quality 500 to 550 watt psu will have a +12 volt rail rated at 40 amps. A high quality 700 to 750 watt psu will have a +12 volt rail rated at 60 amps.

In addition the power supply should be at least 80+ Bronze certified for energy efficiency. There are some models available which have achieved 80+ Silver and 80+ Gold Certifications.

Corsair, PC Power & Cooling, and Seasonic are some of the brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Some of the newer models come with a 7 year warranty. Lately we've been seeing a few other brands offering some high quality units. One example would be the Antec Earthwatts series which is a major improvement over Antec’s older psu’s like the Basiq models.

Two video cards in Crossfire or SLI mode are a complete waste of time for the mainstream applications you will be using . One good video card is sufficient. Your applications, including the Adobe packages, are cpu and memory intensive rather than video intensive. That being the case a high quality 500 to 550 watt power supply is sufficient. I recommend something like the Corsair VX550.

DDR 1300 memory is the current sweet spot but for your specific applications I recommend bumping it up to DDR3 1600 memory.

Coolermaster makes a 1050 watt unit ?
For the 4670 you could run it on a 450W unit and not have any problems, i certainly wouldnt go any higher than 650W because you will start running your PSU at super low load and the efficiency will plummet, a 1KW unit isnt useful unless you plan to run 3 GTX285's in SLI or a similar configuration.


Jan 8, 2010
so the Corsair 650w is recommended instead then...

As I say, Im new to all this and was offered the 1050 watt as an alternative to the 650 watt PSU for a small additional charge, but I think for the extra £20 I could get the Corsair, if thats the best way to go....
The Corsair TX series power supplies do not have modular power cables. All power cables are permanently hardwired to the psu.

The Corsair HX series power supplies have some modular power cables for components and peripherals. The main power cables are still permanently hardwired but cables for drives and other peripherals are modular. The idea is that you only plug in the cables you actually need. That should make for better cable management inside the case.


Jan 8, 2010
I've been told that the Corsairs put out around 35db, the Collermaster is around 22db... As the computer is for making music I need the PSU to be as quiet as possible, any suggestions on this front?
Yes - The brand new Seasonic X650 Gold Certified power supply is very quiet.

Here is a link to a technical review over at Silent PC Review:


It is one of only 3 power supplies in the 600 to 650 watt range to ever make their recommended quiet psu list during the past 5 years.

Here is a link to a regular technical review over at jonnyguru.com:


Currently available at newegg.com and other online vendors:



I agree, 650watt should be fine. Most devices are over-estimated anyway.

I realized this when I bought my xp2500+, it was recommended to have *at least* a 350watt PSU. Using kill-a-watt, my entire computer WITH 90watt CRT and 505watt 5.1 stereo at 1/4 volume while playing games was only pulling ~175watts at the wall with my nvidia-5900fx.

I probably could have ran my machine with a 175watt PSU just fine.