new system,old psu any good?

[jhogg]

I'm looking to build a new system but would like to use my current psu which is an akasa paxpower 460watt
new system would be this:
C2D 6300 or 6400
gigabyte ds3 mobo
2gb 6400 ram
8800gts gfx card
250gb sata hard drive
sata dvdrw drive
case has 3x12cm fans & 1x8cm fan
Would my psu be capable of running this system stably?

[Agent]

With ease
You will need to get a seperate cable to hook up the 8800gts if you dont already have one. Other than that, its fine

[chuckskull]

Yup as agent said it'll be fine. If you add another 8800GTS you'll need a bigger one, but you probably guessed that much.

[Supershanks]

your being a little optimistic there running 8800gts gfx card on a 460watt psu. The 8800 uses 185watts almost exclusively from the 12v rail thats 15A 12v b4 you start adding in other components. Have a look here PSU Calculator I think nvidia recomend a psu with 26A 12v as a minimum but personally i'd bre looking 4 a 550/650 unit.

luck

Edit: From Akasa's site

+3.3V ±5% 0.5A 30.0A -
+5V ±5% 0.3A 30.0A -
+12V1 ±5% 1.0A 14.0A 16.0A
+12V2 ±5% 1.0A 15.0A -
-12V ±10% 0.0A 0.5A -
+5Vsb ±5% 0.0A 2.0A 2.5A

On a 2 rail psu 12v1 is used exclusively by CPU. That gives 12v2 to serve all other components so u have 15A oh yes just enough for 8800 now what about the fans drives etc., Look for a bigger unit

[Papa Lazarou]

I'd use it

[Agent]

edit - just checking somthing

[Agent]

your being a little optimistic there running 8800gts gfx card on a 460watt psu. The 8800 uses 185watts almost exclusively from the 12v rail thats 15A 12v b4 you start adding in other components. Have a look here PSU Calculator I think nvidia recomend a psu with 26A 12v as a minimum but personally i'd bre looking 4 a 550/650 unit.

luck

Edit: From Akasa's site
On a 2 rail psu 12v1 is used exclusively by CPU. That gives 12v2 to serve all other components so u have 15A oh yes just enough for 8800 now what about the fans drives etc., Look for a bigger unit

Exclusively ? - I didnt realise that. I was under the understanding that while it would use 12v1,it wasnt enirely for the CPU (thats a lot of ampage wasted if so !)

If this is the case, then i agree, look for a higher rated PSU to keep the worrying at bay. A few calculations:

8800gts = 2 power (1 PCIe, one external) = 150watt total (each can supply a max. of 75watt) = 12.5A
14A (rail 2) - 12.5A = 1.5A left. ie, not much

This of course assumes 100% ampage load from the 8800gts (unlikely, but needs to be calculated) and that the above from Supershanks about the 12v1 rail is correct.

Id be tempted to try it first and see how it goes. Thats a decent PSU, so you dont need to worry about it exploding like a Q-tec
If it doesnt manage, buy a new one. Atleast you know where the issue is if you get issues

[Supershanks]

Coming from the amd many amd users were #issed with intels input that bought about multi rail pasus. They work fine for the high voltage pentium 4s but are a waste of resource otherwise.

This is 1 of the more polite (& knowledgable) posts.
PSU's---2 x 12v---The Dual Rail Myth

luck

[Papa Lazarou]

The Tagan PSU I have allows you to combine the 12v rails into one if you want.

I note on the PSU calculator you linked to, there is an interesting setting called power supply utilization (default is 100% - peak power). Changing this makes a drastic difference to the PSU output recommended. I can't see an explanation for what this setting does on the page though

My assumption is that many no name manufacturers (and dodgy ones with a name for that matter) rate their PSUs by peak power output. In other words they might just provide the specified wattage for a very short period of time, but won't like it very much. Very good ones on the other hand obviously have a much more conservative way of rating their PSU, e.g I beleive Seasonic's are achieving high efficiency even at 100% of their advertised output. Presumably the "peak" output of a quality PSU like the Seasonic would be a lot higher than the advertised output.

So is the adjustment on this page maybe to allow for this? I.e you choose 100% utilisation if using a generic PSU, but can use a lower utilisation if choosing a good quality one.

[chuckskull]

Yup I know on my Hiper Type-R it's advertised as 580w but the peak is closer to 650w. A good 400w PSU will be better than a cheap 800w one everytime.

[Reapsy]

I really fancy one of these

http://www.pcpower.com/products/view...php?show=S75QB

I asked about shipping to the UK and the general manager emailed me saying the shipping cost would be $58. Given the weak dollar/strong pound atm $257 = £130 which is a pretty good price I think for one of these. Even with import tax it would be £150.

[Supershanks]

I note on the PSU calculator you linked to, there is an interesting setting called power supply utilization (default is 100% - peak power). Changing this makes a drastic difference to the PSU output recommended. I can't see an explanation for what this setting does on the page though

I understand what their doing but like yo say it could be clearer.

you don't want a psu running at max load all the time:-
it loses efficiency, due to heat , more prone to fluctuatiating voltages, runs noisy due to max fan. The solution is to have a operating maximum - this is a load which the psu can deliver without overheating, & is stable & quiet, this also leaves headroom for ocing & some expansion. 75~80% is usually about right.

I disagree with the way the % is applied:-

The maximum load from the sum of components should be factored up by the operating max.

for example total max poweer from components = 380
80% Max op load So power needed = 380W/80% = 475Watts. So a 480W psu will be able to handle the selected components whilst running at 80% of max load.

At 100% Power needed is 380w/100% =380W but this PU will be running flat out to provide the needed max power.

Tagan make somer great & innovative PSU's.

[Agent]

Yup, I love the rail selection option on Tagans

Does anyone know of any other PSU's which do this, out of curiosity ? - Not seen any

[Smokey21]

This is a very good read, for info on PSU's:
http://www.xtremesystems.org/forums/...d.php?t=108088

[Supershanks]

One of my favourite psu guys is here JonnyGuru
+ PSU Recommendations for High End Gaming PC's

@Reapsy tht's a pretty good deal on that PCP&C Silencer 750 Quad (Black) I just got the etasis 850 from scan 4 £129 which is around £40 cheaper than other 850's, but might have considered that had i seen it

luck

[Blitzen]

Yup I know on my Hiper Type-R it's advertised as 580w but the peak is closer to 650w. A good 400w PSU will be better than a cheap 800w one everytime.

Peak Power is a strange concept.

I can guarantee you that if your PC drew anything anywhere near the 650W for more than a few seconds your Hiper, and most of your components would be nothing more than paperweights.

Thats how you tell a cheap PSU like a Hiper from a good brand PSU. The better PSUs can actually continually sustain there rated power outputs.