What size PSU

I'm considering getting something like this

http://www.novatech.co.uk/novatech/s...tml?MBB-P5NQ66

Into i'll plug my ASUS EN8800GTX, a DVD RW drive, and 4 SATAII HDD's

I already have a rather nice 480watt PSU to hand if it'll be enough for
all that.

... so the question is what size PSU would you stick in the case? (I
guess i'm expecting a few to say as BIG as possible!!) ;-)


Boff.

TheBoffin wrote:
I'm considering getting something like this

http://www.novatech.co.uk/novatech/s...tml?MBB-P5NQ66

Into i'll plug my ASUS EN8800GTX, a DVD RW drive, and 4 SATAII HDD's

I already have a rather nice 480watt PSU to hand if it'll be enough for
all that.

.. so the question is what size PSU would you stick in the case? (I
guess i'm expecting a few to say as BIG as possible!!) ;-)


Boff.

It would have been more fun, if you mentioned the make and model of
power supply you already had. The supply has a label with all sorts
of trivia printed on the side.

One thing your new supply should have, is PCI Express power connectors
to match those on the end of the 8800GTX. Once you locate a supply
with those on it, there is a good chance it'll be the right size
for the job.

Q6600, G0 stepping, 95W. (95W/12V) * (1/0.90) = 8.8 amps on 12V2. That
is the little 2x2 power connector that feeds the processor, and the
processor will draw a maximum of 8.8 amps through it.

http://processorfinder.intel.com/det...px?sSpec=SLACR

The rest of the electrical loads are on 12V1 (if the supply has two
output rails).

8800GTX is here.
http://www.xbitlabs.com/articles/vid...roundup_6.html

8800GTX 127.6W/12V = 10.63 amps

Four disk drives @ 0.6A, gives 2.4A from 12V1 (disks idling in the desktop)

One optical drive, estimate 1.5A from 12V1 (optical media in the tray)

Three fans, totalling 0.5A from 12V1

Total 12V1 is 10.63 + 2.4 + 1.5 + 0.5 = 15.03 amps

Now, look at your 480W supply, and see the amps limits for 12V2 and 12V1.

The next check, is total watts. I assume 50W for motherboard and RAM,
and that comes from the 3.3V and 5V rails. I throw in 10W for the +5VSB rail.
The disks use 5V @ 1A for the controller (12V is for the motor). Optical
is 5V @ 1.5A.

Watts = 12V * (8.8 + 15.03) + 50 + 10 + 5*4 + 5*1.5 = 373.46 watts

That might be the power taken while playing a game, assuming the quad
runs at 100% (and it won't). The Quad runs at full power, when doing
certain multimedia applications, but game loading tends to be
asymmetric. In any case, the above number of watts is generous.

So, when you look at your 480W supply, the thing it won't meet, is the
15A load on 12V1.

When you buy a supply, you might consider looking for one with good
efficiency numbers. If the efficiency is not stated, it'll be about
68% efficient, and the power supply will run like a toaster. The
best supplies, run at 85% efficiency. To see what that means, consider...

373W / 0.85 = 439W (total power from the wall)

439 - 373 = 66W (that is the waste heat output of the efficient supply)

If you used a 68% efficient supply, the waste heat is 176W, and the
supply runs warmer.

Don't forget the connectors. You want two 2x3 connectors. Check the
pictures on the card you're getting, and verify they look like this
one.

http://c1.neweggimages.com/NeweggIma...143-080-05.jpg

This supply has two 2x3 connectors, and a generous 12V output. It
is 7.1" deep and perhaps a bit longer than your existing supply.

Silencer 610W £70.41 inc vat 83% efficient, 0.99 PFC.
http://www.dabs.com/productview.aspx?Quicklinx=4RVF
http://www.pcpower.com/downloads/specs_3825.pdf

Also, check the dimensions of the 8800GTX, and make sure it isn't
going to bump into the disk drives or optical drive.

HTH,
Paul

Paul wrote:
It would have been more fun, if you mentioned the make and model of
power supply you already had. The supply has a label with all sorts
of trivia printed on the side.

One thing your new supply should have, is PCI Express power connectors
to match those on the end of the 8800GTX. Once you locate a supply
with those on it, there is a good chance it'll be the right size
for the job.

Q6600, G0 stepping, 95W. (95W/12V) * (1/0.90) = 8.8 amps on 12V2. That
is the little 2x2 power connector that feeds the processor, and the
processor will draw a maximum of 8.8 amps through it.

http://processorfinder.intel.com/det...px?sSpec=SLACR

The rest of the electrical loads are on 12V1 (if the supply has two
output rails).

8800GTX is here.
http://www.xbitlabs.com/articles/vid...roundup_6.html

8800GTX 127.6W/12V = 10.63 amps

Four disk drives @ 0.6A, gives 2.4A from 12V1 (disks idling in the desktop)

One optical drive, estimate 1.5A from 12V1 (optical media in the tray)

Three fans, totalling 0.5A from 12V1

Total 12V1 is 10.63 + 2.4 + 1.5 + 0.5 = 15.03 amps

Now, look at your 480W supply, and see the amps limits for 12V2 and 12V1.

The next check, is total watts. I assume 50W for motherboard and RAM,
and that comes from the 3.3V and 5V rails. I throw in 10W for the +5VSB
rail.
The disks use 5V @ 1A for the controller (12V is for the motor). Optical
is 5V @ 1.5A.

Watts = 12V * (8.8 + 15.03) + 50 + 10 + 5*4 + 5*1.5 = 373.46 watts

That might be the power taken while playing a game, assuming the quad
runs at 100% (and it won't). The Quad runs at full power, when doing
certain multimedia applications, but game loading tends to be
asymmetric. In any case, the above number of watts is generous.

So, when you look at your 480W supply, the thing it won't meet, is the
15A load on 12V1.

When you buy a supply, you might consider looking for one with good
efficiency numbers. If the efficiency is not stated, it'll be about
68% efficient, and the power supply will run like a toaster. The
best supplies, run at 85% efficiency. To see what that means, consider...

373W / 0.85 = 439W (total power from the wall)

439 - 373 = 66W (that is the waste heat output of the
efficient supply)

If you used a 68% efficient supply, the waste heat is 176W, and the
supply runs warmer.

Don't forget the connectors. You want two 2x3 connectors. Check the
pictures on the card you're getting, and verify they look like this
one.

http://c1.neweggimages.com/NeweggIma...143-080-05.jpg

This supply has two 2x3 connectors, and a generous 12V output. It
is 7.1" deep and perhaps a bit longer than your existing supply.

Silencer 610W £70.41 inc vat 83% efficient, 0.99 PFC.
http://www.dabs.com/productview.aspx?Quicklinx=4RVF
http://www.pcpower.com/downloads/specs_3825.pdf

Also, check the dimensions of the 8800GTX, and make sure it isn't
going to bump into the disk drives or optical drive.

HTH,
Paul


Wow Paul --- thankyou very much for that informative and usefully
verbose response.

I'm probably going to house the new MB in a new larger case any how;
but the existing PSU I have at hand is an Enermax Cooler Giant 480W
(EG485AX-VHB(G) SFMA V2.0) -- not sure how much of that code is needed ;-)

+3.3V +5V +12V1 +12V2 -12V +5Vsb +3.3V & +5V
0.5A/34A 0.3A/40A 0.5A/16A 0.5A/15A 0A/0.8A 0A/2.5A 280W

Boff.

Paul wrote:

The
best supplies, run at 85% efficiency.


"That's quite a claim, it would be the best PSU I've ever seen." said
silentpc.com challenging Antec's marketing.

When they then measured an astonishing 86-88% efficiency in a (albeit
small and useless mostly today) PSU.

http://www.silentpcreview.com/article188-page3.html

Thank you for taking the time to write up that PSU primer, you can't
make an informed PSU decision unless you understand their input and
output capabilities beyond the marketing blather.

Paul wrote:


This supply has two 2x3 connectors, and a generous 12V output. It
is 7.1" deep and perhaps a bit longer than your existing supply.

Silencer 610W £70.41 inc vat 83% efficient, 0.99 PFC.
http://www.dabs.com/productview.aspx?Quicklinx=4RVF
http://www.pcpower.com/downloads/specs_3825.pdf


Nice looking PSU, sounds the business

How's this one compare do you think? ThermalTake ToughPower Series Cable
Management 750W active @ £77.55 inc vat
http://www.novatech.co.uk/novatech/s....html?TT-W0116

I'll probably be getting all my kit from Novatech as these guys are just
down the road from me; used them loads before - quite happy with them.


Boff

TheBoffin wrote:
Paul wrote:
It would have been more fun, if you mentioned the make and model of
power supply you already had. The supply has a label with all sorts
of trivia printed on the side.

One thing your new supply should have, is PCI Express power connectors
to match those on the end of the 8800GTX. Once you locate a supply
with those on it, there is a good chance it'll be the right size
for the job.

Q6600, G0 stepping, 95W. (95W/12V) * (1/0.90) = 8.8 amps on 12V2. That
is the little 2x2 power connector that feeds the processor, and the
processor will draw a maximum of 8.8 amps through it.

http://processorfinder.intel.com/det...px?sSpec=SLACR

The rest of the electrical loads are on 12V1 (if the supply has two
output rails).

8800GTX is here.
http://www.xbitlabs.com/articles/vid...roundup_6.html

8800GTX 127.6W/12V = 10.63 amps

Four disk drives @ 0.6A, gives 2.4A from 12V1 (disks idling in the
desktop)

One optical drive, estimate 1.5A from 12V1 (optical media in the tray)

Three fans, totalling 0.5A from 12V1

Total 12V1 is 10.63 + 2.4 + 1.5 + 0.5 = 15.03 amps

Now, look at your 480W supply, and see the amps limits for 12V2 and 12V1.

The next check, is total watts. I assume 50W for motherboard and RAM,
and that comes from the 3.3V and 5V rails. I throw in 10W for the
+5VSB rail.
The disks use 5V @ 1A for the controller (12V is for the motor). Optical
is 5V @ 1.5A.

Watts = 12V * (8.8 + 15.03) + 50 + 10 + 5*4 + 5*1.5 = 373.46 watts

That might be the power taken while playing a game, assuming the quad
runs at 100% (and it won't). The Quad runs at full power, when doing
certain multimedia applications, but game loading tends to be
asymmetric. In any case, the above number of watts is generous.

So, when you look at your 480W supply, the thing it won't meet, is the
15A load on 12V1.

When you buy a supply, you might consider looking for one with good
efficiency numbers. If the efficiency is not stated, it'll be about
68% efficient, and the power supply will run like a toaster. The
best supplies, run at 85% efficiency. To see what that means, consider...

373W / 0.85 = 439W (total power from the wall)

439 - 373 = 66W (that is the waste heat output of the
efficient supply)

If you used a 68% efficient supply, the waste heat is 176W, and the
supply runs warmer.

Don't forget the connectors. You want two 2x3 connectors. Check the
pictures on the card you're getting, and verify they look like this
one.

http://c1.neweggimages.com/NeweggIma...143-080-05.jpg

This supply has two 2x3 connectors, and a generous 12V output. It
is 7.1" deep and perhaps a bit longer than your existing supply.

Silencer 610W £70.41 inc vat 83% efficient, 0.99 PFC.
http://www.dabs.com/productview.aspx?Quicklinx=4RVF
http://www.pcpower.com/downloads/specs_3825.pdf

Also, check the dimensions of the 8800GTX, and make sure it isn't
going to bump into the disk drives or optical drive.

HTH,
Paul


Wow Paul --- thankyou very much for that informative and usefully
verbose response.

I'm probably going to house the new MB in a new larger case any how; but
the existing PSU I have at hand is an Enermax Cooler Giant 480W
(EG485AX-VHB(G) SFMA V2.0) -- not sure how much of that code is needed ;-)

+3.3V +5V +12V1 +12V2 -12V +5Vsb +3.3V & +5V
0.5A/34A 0.3A/40A 0.5A/16A 0.5A/15A 0A/0.8A 0A/2.5A 280W

Boff.


Your 12V2 is right on the edge. The calculated value is 15.03A and
the power supply has a 15A limit. So now you get to buy a new one :-)

Paul

Paul wrote:
TheBoffin wrote:
Paul wrote:
It would have been more fun, if you mentioned the make and model of
power supply you already had. The supply has a label with all sorts
of trivia printed on the side.

One thing your new supply should have, is PCI Express power connectors
to match those on the end of the 8800GTX. Once you locate a supply
with those on it, there is a good chance it'll be the right size
for the job.

Q6600, G0 stepping, 95W. (95W/12V) * (1/0.90) = 8.8 amps on 12V2. That
is the little 2x2 power connector that feeds the processor, and the
processor will draw a maximum of 8.8 amps through it.

http://processorfinder.intel.com/det...px?sSpec=SLACR

The rest of the electrical loads are on 12V1 (if the supply has two
output rails).

8800GTX is here.
http://www.xbitlabs.com/articles/vid...roundup_6.html

8800GTX 127.6W/12V = 10.63 amps

Four disk drives @ 0.6A, gives 2.4A from 12V1 (disks idling in the
desktop)

One optical drive, estimate 1.5A from 12V1 (optical media in the tray)

Three fans, totalling 0.5A from 12V1

Total 12V1 is 10.63 + 2.4 + 1.5 + 0.5 = 15.03 amps

Now, look at your 480W supply, and see the amps limits for 12V2 and
12V1.

The next check, is total watts. I assume 50W for motherboard and RAM,
and that comes from the 3.3V and 5V rails. I throw in 10W for the
+5VSB rail.
The disks use 5V @ 1A for the controller (12V is for the motor). Optical
is 5V @ 1.5A.

Watts = 12V * (8.8 + 15.03) + 50 + 10 + 5*4 + 5*1.5 = 373.46 watts

That might be the power taken while playing a game, assuming the quad
runs at 100% (and it won't). The Quad runs at full power, when doing
certain multimedia applications, but game loading tends to be
asymmetric. In any case, the above number of watts is generous.

So, when you look at your 480W supply, the thing it won't meet, is the
15A load on 12V1.

When you buy a supply, you might consider looking for one with good
efficiency numbers. If the efficiency is not stated, it'll be about
68% efficient, and the power supply will run like a toaster. The
best supplies, run at 85% efficiency. To see what that means,
consider...

373W / 0.85 = 439W (total power from the wall)

439 - 373 = 66W (that is the waste heat output of the
efficient supply)

If you used a 68% efficient supply, the waste heat is 176W, and the
supply runs warmer.

Don't forget the connectors. You want two 2x3 connectors. Check the
pictures on the card you're getting, and verify they look like this
one.

http://c1.neweggimages.com/NeweggIma...143-080-05.jpg

This supply has two 2x3 connectors, and a generous 12V output. It
is 7.1" deep and perhaps a bit longer than your existing supply.

Silencer 610W £70.41 inc vat 83% efficient, 0.99 PFC.
http://www.dabs.com/productview.aspx?Quicklinx=4RVF
http://www.pcpower.com/downloads/specs_3825.pdf

Also, check the dimensions of the 8800GTX, and make sure it isn't
going to bump into the disk drives or optical drive.

HTH,
Paul


Wow Paul --- thankyou very much for that informative and usefully
verbose response.

I'm probably going to house the new MB in a new larger case any how;
but the existing PSU I have at hand is an Enermax Cooler Giant 480W
(EG485AX-VHB(G) SFMA V2.0) -- not sure how much of that code is needed
;-)

+3.3V +5V +12V1 +12V2 -12V +5Vsb +3.3V & +5V
0.5A/34A 0.3A/40A 0.5A/16A 0.5A/15A 0A/0.8A 0A/2.5A 280W

Boff.


Your 12V2 is right on the edge. The calculated value is 15.03A and
the power supply has a 15A limit. So now you get to buy a new one :-)

Paul

Try that again :-) (Post in haste, regret at leisure...) Got my
rails mixed up.

That Enermax supply isn't bad. It is 75% efficient. The rating on the supply
is 12V1 @ 16A, and the calculated load is 15.03A. So, by rating alone,
you can use it if you want. If I was buying it for myself, I'd want to see
about a 3 amp margin, so 12V1 @ 18A or so. It is a coin toss, whether
you continue to use the current supply or not. If you're tight for
money, you could carry on with the one you've got.

http://web.archive.org/web/200502062...supp/index.htm

Sorry about that,
Paul

You would be far better off with that many power drawing components to
seriously consider a 650 Watt PSU. If you overtax a PSU because it is
underpowered you risk frying your computer.

--
--DaveW
"TheBoffin" wrote in message
...
I'm considering getting something like this

http://www.novatech.co.uk/novatech/s...tml?MBB-P5NQ66

Into i'll plug my ASUS EN8800GTX, a DVD RW drive, and 4 SATAII HDD's

I already have a rather nice 480watt PSU to hand if it'll be enough for
all that.

.. so the question is what size PSU would you stick in the case? (I guess
i'm expecting a few to say as BIG as possible!!) ;-)


Boff.

Paul wrote:
Paul wrote:

Try that again :-) (Post in haste, regret at leisure...) Got my
rails mixed up.

That Enermax supply isn't bad. It is 75% efficient. The rating on the
supply
is 12V1 @ 16A, and the calculated load is 15.03A. So, by rating alone,
you can use it if you want. If I was buying it for myself, I'd want to see
about a 3 amp margin, so 12V1 @ 18A or so. It is a coin toss, whether
you continue to use the current supply or not. If you're tight for
money, you could carry on with the one you've got.



Paul thanks for the info, much appreciated. Considering the Enermax
only has one dedicated 6pin connector, and i'll need 2 for the 8800GTX
... and considering that it's fairly close to the limit; and i'm likely
to add an extra PCI card or two (not sure whether i'll use the MB sound
or plug in the SoundBlaster X-Fi i've got); plus i'm guessing there'll
be current draw from using things like USB devices ... perhaps in
reality your initial statement of it being right on the line is probably
closer to the truth.

For the sake of £70ish i'd much rather have a stable PC that doesn't
stress itself powerwise too much and can keep cool(ish); than one
that's overheating or every now and again is unable to meet the demands
and Windoze throws a BSOD!

So I think things considered, I may well opt for a more powerful PSU.
What was your opinion on the Thermaltake ?
http://www.novatech.co.uk/novatech/s....html?TT-W0116


Boff

DaveW wrote:
You would be far better off with that many power drawing components to
seriously consider a 650 Watt PSU. If you overtax a PSU because it is
underpowered you risk frying your computer.


Frying? is that what honestly happens ... I'd have just thought it
would be about as stable as a ZX81 with a RAMPAC velcro'd in ;-)

So just to get it into context for me; if a PSU is underpowered and you
load it up - say maybe launch UT3 ;-) ... are we talking burnout MB /
CPU / RAM ... large plume of smoke as the house burns down ???

(not that i'm going to risk it anyhow - i've already come to the
decision the a larger PSU is required)

Boff.