450 or 550 watt CWT??

[BoB_DoG]

Okay, Im fairly happy that CWT's and Antecs are one and the same..even if this isnt the case, theyre still respectable PSU's. What Im wondering is, do i need to shell out an extra 25 quid for a 550watt PSU. At the moment Im running on a Cheiftec 360watt one that came with my case. With the imminent addition of a second HDD, and possible unplanned future upgrades, it seems wise to pick up a new PSU with my HDD to save postage (tight yes I know).

Anyway, at the moment im running:

NF7-S
1800XP 2.1Ghz (1.65v)
1x 120Gb 'Cuda (soon to be joined by second)
Radeon 8500LE 128Meg
52x Asus CD-R/RW
Toshiba 12x DVD ROM
plus 4 Papst fans (and a volcano 12 which I should really change)

so to recap, is 450w gonna be futureproof enough, also anyone who has one, are they silent(ish), cos if so I'll get a new HSF to make my rig a bit quieter (it runs 24/7 in my uni room)

cheers

BoB_DoG

[SilentDeath]

tbh id say go for the 550w. they dont cost THAT much more.
ive got the 550w. i CANT say this psu is great for a few resons.

assuming your buying from scan (where else can you get them?), the 550w model is the CWT-550ADP. it also says EPS12V on the sticker - think it means enhanced 12v or something. this would be future proofed a bit as iirc high performance severs use EPS12V - somehting that might move to normal pcs in future? this is slightly annoying though - the mobo connectors are bigger for EPS12V so you have to use the bundled converter - adds resistance and will lower the rails a TINY bit shouldnt make much differnce though.
there are plenty (imo too many) molex connector cables which are very long. that said i only use 2 molexs in total - one plugs into my extension that connects my hdds 2 fans and my 9700, the other goes out the back of my case to my fans on my heatercore. my hdds are at top of my case in the cd bays allowing me to hide all the unneeded cables neatly

also note the 450w on scan - there is no A series 450w on cwt site. so its got to be a B series - this means the +3.3 and +5v rails will have a combined max which is slightly lower than the individual ratings added up. this gives a 55w difference between the +5+3.3 rails on teh 550w and 450w psus. the b series is definatly a lot less good - having 5% tollerance on each rail instead of the 3% on the 550w (A series)

im running nf7-s r2 @ 220fsb 1.7vdd
1700+ @ 2.3ghz 1.9v
9700np @ 450 core 1.75v/315
p105 4x dvd-rw
3 maxtor hdds giving me 300gb
10 fans
and some other crap

these are my voltages atm
VCore: 1.89V, VMem: 2.69V, +3.3: 3.23V, +5.00: 4.89V, +12.00: 11.67V, -12.00: -11.86V, -5.00: 3.55V

only the 3.3, 5 and 12v are worth looking at. they are all well within the 3% tollerance intel says in its specs for p4 btw - the psu is great.

resistance in the mobo could be causing them to appear low
my multimeter, if accurate (i think it is) gets: 5v - 5.09 12v - 11.98

so with the 12v for example, there is 0.35v being lost between the psu and the chip on mobo for measuring - assuming both volt meters are accutate.
none of the rails drop any amount worth saying at all under load - very good.

one thing to point out - my (unbranded) 350w achived as good readings from mobo (my nf7-s v1.1, now i have a v2 board - so they arnt really compareable results). under little load it got 11.83 on the +12v, under load it dropped to 11.67. the 5v didnt ever drop. the 3.3v droped by 0.1. this psu measured 12.15v and 5.06v with multimeter which might be why the unloaded results were better.
the cheiftec psu you said is one from this page. the specs are v similar to my 350w but slightly worse
also note, in the above link for the psu specs that the +3v is exactly the same as my 350w psu. the +5v is 5A higher, the 12v is 8.5A higher!! (note the sticker on mine says 36A for 12v, on the specs it says 24A for the same model!)
the high 12v rating would be great for running pelters and should be fine for 150w ones with a pc runnign aswell. with no pc it is capable of 245w ones but dont expect it to last v long under full load.

that said, 12v is least used and least important - for now, untill EPS12v becomes normal which i think wont be long (amd64 mobos will probly all use this eventaully)
this means that this psu wont be that much better than a good brand 350w psu for now - though only really true for antec and CWT psus as they are only ones to have seperate rails. - on other psus load on the 5v will make the other rails drop slighlty, antecs and CWTs wont. the combined rating for 3.3+5v on my 350w is 210w - far from the 280w it should be if (3.3*32)+(5*35) is done..

also note that the cwt550 psu is compleatly silent (it also has a fan monototing cable!!! - reads 1500-1550 in mbm5). the casing does get slightly warm on the top (pc is mounted on the top so it would be warmest part). and looks v nice. the casing is either steel or alu, cant remeber how heavy it was but i think it was a lot lighter than my 350w so id say alu. the main atx cable is braided (= good) the rest arnt. the atx converter extension thingy isnt braided though.
the psu has no voltage selection switch on back, so it can ONLY be used with 230v mains (this will varie from country to county - anywhere between 200 and 260v should be safe) so it cant be used in the US[/b]. if you take the lid off there maybe easy way to change it but id assume if they left the swtich out to save money, they would also use a transformer without the 115v primary coil aswell (there are usually two coils so you can select the input voltage). imo not worth the risk if you plan to use in US and it probly wouldnt be an easy mod anyway if it could be done.

there is a power switch on back so you can turn it off there instead of mains if you want no power in mobo (there is usually +5v sb going thru the mobo when the psu is on) - usefull if upgrading anything. ground should still be connected when this swtich is off so you can still use to ground yourself from static when upgrading stuff

imo the 550w is a lot higher quality and it is still £30 cheaper than the antec version - exactly the same, so it is worth it. the 450w is a worse model and thats why its so much cheaper

(sorry for the v long post - this has not been at all easy with hexus's buggy thingy where the typing box only takes HALF my screen, hope it can be fixed and ill suggest now in the suggestion forum thingy)

[BoB_DoG]

cheers for the comprehensive answer, It has sorted out all the questions that I need to know, and told me a few that i wouldnt have asked, but in hindsight are useful to know, like the adapter for the mobo.

Think Im gonna buy the 550W, and I may as well grab some more rubbishrubbishrubbishrubbish from scan, as Im paying a tenner P&P already.

Thanks again dude

[SilentDeath]

np
i would have stoped ages ago but i was trying to remember something which i just have,its not realted to psus, but i can now goto sleep

[BUFF]

Originally posted by |SilentDeath|

the psu has no voltage selection switch on back, so it can ONLY be used with 230v mains (this will varie from country to county - anywhere between 200 and 260v should be safe) so it cant be used in the US. [/B]

It is possible that it can autodetect & adjust accordingly (yes, PSU's like that do exist).