NEW BUILD - am I going to need a more powerful PSU? And one other question.


A

a

Hey everyone, I'm going to build me a new machine, I'm not sure if my
power supply (a 520 watt Corsair) can handle all this. Here's what
I've decided on:

CPU - Core i5-2500
Motherboard - BIOSTAR TZ68A+
RAM - 2 x 4GB CORSAIR
Video card - EVGA GeForce GTX 560
Hard drive - Mushkin Enhanced Chronos Deluxe 2.5" 60GB
Win7 x64 Home Premium

I also have a 250 gb and an 80 gb hard drive as well as my DVD drive.


Also, if I decide to add more RAM does it matter very much if I use
one 4 gb stick vs. 2 x 2 gb? I know you're supposed to have matching
pairs for it to run in dual channel mode but how big is the
difference?


thanks for any advice you can give.
Jon
 
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P

Paul

Hey everyone, I'm going to build me a new machine, I'm not sure if my
power supply (a 520 watt Corsair) can handle all this. Here's what
I've decided on:

CPU - Core i5-2500
Motherboard - BIOSTAR TZ68A+
RAM - 2 x 4GB CORSAIR
Video card - EVGA GeForce GTX 560
Hard drive - Mushkin Enhanced Chronos Deluxe 2.5" 60GB
Win7 x64 Home Premium

I also have a 250 gb and an 80 gb hard drive as well as my DVD drive.


Also, if I decide to add more RAM does it matter very much if I use
one 4 gb stick vs. 2 x 2 gb? I know you're supposed to have matching
pairs for it to run in dual channel mode but how big is the
difference?


thanks for any advice you can give.
Jon

There is a GTX560 here, listed at 160 watts.

http://www.xbitlabs.com/articles/graphics/display/powercolor-hd6950-1gb_3.html#sect0

160 + 95/0.9 watts + 50 watts motherboard/ram + 2*12W HDD + 25W ODD + 10W USB gives 375W.
The 25W for the optical drive is a boilerplate number, while a real measurement
might be closer to 17W. The hard drives also vary, and sometimes you can look them up.
Some hard drives only use half the power of my placeholder 12W number.
The 50W is intended to cover the chipset, and not all chipsets will use
all of that. Especially now that some functions are housed in the processor,
so the processor "pays the power bill". RAM doesn't use very much at all any more
(download a Kingston datasheet, to get a round number per stick). So the number
really isn't 374W, it's a bit less.

Corsair 520HX ratings.

http://images10.newegg.com/NeweggImage/productimage/17-139-001-04.jpg

180W on low voltage rails (your loading is about 70W maybe).
480W on 12V rails (your loading is about 281W)
15W on +5VSB (your loading is 10W estimated placeholder)

Just some rough round numbers.

I don't think any of the rails go past the 18 amp limiters.

*******

If adding RAM, add in quanta of 2x4GB, due to the low price.
The low price on DDR3 RAM, won't stay there forever. The
pricing is starting to kill RAM companies :-(

You can balance RAM, by using the same amount in each channel.
For example, putting 2x2 in Channel0 and a single 4GB stick
in Channel1, would not lose you any performance (that is a three
stick config, with a total of 8GB). But that observation doesn't
help in this case. If you install a 2x4GB kit today, you might
not see an 8GB single stick for some time. And given the prices
of 4GB sticks, I don't see the point in being a cheapskate.
Actually, I'd have to question why you needed more than 2x4GB.
That should last a while, in terms of typical usage patterns.
Another 2x4GB would just be bling. The only time you're going
to fill it up, is running CHKDSK :) (That's a little humor
directed at a bad design decision by Microsoft with regard
to the chkdsk program. Try it. If you install 16GB, it'll try
to use all of that too.)

Paul
 
Y

Yousuf Khan

Hey everyone, I'm going to build me a new machine, I'm not sure if my
power supply (a 520 watt Corsair) can handle all this. Here's what
I've decided on:

CPU - Core i5-2500
Motherboard - BIOSTAR TZ68A+
RAM - 2 x 4GB CORSAIR
Video card - EVGA GeForce GTX 560
Hard drive - Mushkin Enhanced Chronos Deluxe 2.5" 60GB
Win7 x64 Home Premium

I also have a 250 gb and an 80 gb hard drive as well as my DVD drive.


Also, if I decide to add more RAM does it matter very much if I use
one 4 gb stick vs. 2 x 2 gb? I know you're supposed to have matching
pairs for it to run in dual channel mode but how big is the
difference?


thanks for any advice you can give.
Jon

You can do the calculations yourself, rather easily:

http://www.thermaltake.outervision.com/

Yousuf Khan
 
A

a

There is a GTX560 here, listed at 160 watts.

http://www.xbitlabs.com/articles/graphics/display/powercolor-hd6950-1gb_3.html#sect0

160 + 95/0.9 watts + 50 watts motherboard/ram + 2*12W HDD + 25W ODD + 10W USB gives 375W.
The 25W for the optical drive is a boilerplate number, while a real measurement
might be closer to 17W. The hard drives also vary, and sometimes you can look them up.
Some hard drives only use half the power of my placeholder 12W number.
The 50W is intended to cover the chipset, and not all chipsets will use
all of that. Especially now that some functions are housed in the processor,
so the processor "pays the power bill". RAM doesn't use very much at all any more
(download a Kingston datasheet, to get a round number per stick). So the number
really isn't 374W, it's a bit less.

Corsair 520HX ratings.

http://images10.newegg.com/NeweggImage/productimage/17-139-001-04.jpg

180W on low voltage rails (your loading is about 70W maybe).
480W on 12V rails (your loading is about 281W)
15W on +5VSB (your loading is 10W estimated placeholder)

Just some rough round numbers.

I don't think any of the rails go past the 18 amp limiters.

*******

If adding RAM, add in quanta of 2x4GB, due to the low price.
The low price on DDR3 RAM, won't stay there forever. The
pricing is starting to kill RAM companies :-(

You can balance RAM, by using the same amount in each channel.
For example, putting 2x2 in Channel0 and a single 4GB stick
in Channel1, would not lose you any performance (that is a three
stick config, with a total of 8GB). But that observation doesn't
help in this case. If you install a 2x4GB kit today, you might
not see an 8GB single stick for some time. And given the prices
of 4GB sticks, I don't see the point in being a cheapskate.
Actually, I'd have to question why you needed more than 2x4GB.
That should last a while, in terms of typical usage patterns.
Another 2x4GB would just be bling. The only time you're going
to fill it up, is running CHKDSK :) (That's a little humor
directed at a bad design decision by Microsoft with regard
to the chkdsk program. Try it. If you install 16GB, it'll try
to use all of that too.)

Paul


Thanks alot Paul, that was quite the explaination. It looks like
you're telling me I should be OK. As far as not needing more than 8GB,
maybe you are right but I'm not so sure. There will be times when I
will be running XSI (3d modeling), 3dCoat (sculpting and 3d painting),
Photoshop and a game engine (Unity or Unreal 3) all at the same time.
If I'm also running Bridge and Firefox that's another 450+ mb.

thanks again
 
J

John Doe

You can buy a wattage meter for $20, if you really want to know
how much power your system is using and if you want to match it
with the correct power supply.
 
J

John Doe

Yousuf Khan said:
You can do the calculations yourself, rather easily:

If you want an accurate estimation, spend $20 on a wattage meter.
Online power supply calculators are for selling unnecessarily
high wattage power supplies.

--
 
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Paul

Timothy said:
"John Doe" > If you want an accurate estimation, spend $20 on a wattage meter.

So if one did not possess a power supply of sufficient wattage
to run the system at full power, how does one generate the wattage
that is to be measured by the wattmeter?

*TimDaniels*

Recall a certain Calvin and Hobbes cartoon, where Calvin
asks his dad how they figure out how much weight the bridge
they're driving over, can hold. And his dad tells him,
they drive heavier and heavier trucks over the bridge,
until the bridge breaks and falls down.

A computer doesn't draw peak power when you start it, boot
it, and sit idle in the desktop. A typical gamer system with
big video card, only hits peak power, when in 3D gaming mode.
You can connect the Kill-o-Watt meter, and get a reading from
the meter. Then, try a slightly more stressful program,
and so on. Until either the machine trips out, or the machine
stays up, and you know it can take it.

A modern system in idle, shouldn't use more than about 150W or
so. So you should be able to start it, with a crappy supply.
Video card idle power has dropped substantially over the years.
There is one video card, that's down around 2-3 watts or so
at idle. And if you have that "triple SLI system with $2000
worth of video cards", then you're hardly the kind of person
to be running that on a $50 supply. You can pop for a new
$300 supply, because you're made of money. You'd probably
have bought the $300 supply, because it had a pretty logo on the
side of it :) (Bling)

Paul
 
P

Paul

Thanks, that's a pretty handy tool. According to that I only need a
little over 400 watts. Pretty close to Paul's estimate, so way-to-go
Paul.

Jon

My grade five math teacher is proud of me :)

And they said I'd never amount to anything.

Paul
 
J

John Doe

Timothy Daniels said:
:

So if one did not possess a power supply of sufficient wattage
to run the system at full power, how does one generate the
wattage that is to be measured by the wattmeter?

I'm trying to promote science instead of marketing (and maybe the
idea of comparing power supply size with other boys). You can
measure the actual wattage of your current system and compare that
to an online power supply calculator that is intended to sell
overpowered power supplies. That will surprise you. Or, like Paul
said, you can avoid stressing the system. Or, start with a
low-power substitute for the video card.

If you're willing to spend so much on a system(s), you may as well
know what you're doing. Besides, if you are scientifically
oriented, seeing what's happening power wise when running your
system is fun (at least for a while).

--
 
Y

Yousuf Khan

If you want an accurate estimation, spend $20 on a wattage meter.
Online power supply calculators are for selling unnecessarily
high wattage power supplies.

The point is to get a pre-estimate of the power needed *before* you buy
the PSU. The wattmeter will only tell you what your current system power
usage is.

Yousuf Khan
 
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J

John Doe

Yousuf Khan said:
John Doe wrote:

The point is to get a pre-estimate of the power needed *before*
you buy the PSU. The wattmeter will only tell you what your
current system power usage is.

I refuted that in the text that you snipped.
Scroll up.

--
 
Y

Yousuf Khan

I refuted that in the text that you snipped.
Scroll up.

You refuted nothing, you had nothing else to say, beyond you saying you
refuted it.

The online PSU calculators are good tool to get you started, if you want
to buy underpowered PSU's after that, then it's your choice.

Yousuf Khan
 
L

Loony

My grade five math teacher is proud of me :)

And they said I'd never amount to anything.

Paul

.....and, as usual Paul, they're the ones that never amounted to
anything. My story was similar and none of them ever got a Ph.D.

:)
 
T

Ting Hsu

Hey everyone, I'm going to build me a new machine, I'm not sure if my
power supply (a 520 watt Corsair) can handle all this. Here's what
I've decided on:

CPU - Core i5-2500
Motherboard - BIOSTAR TZ68A+
RAM - 2 x 4GB CORSAIR
Video card - EVGA GeForce GTX 560
Hard drive - Mushkin Enhanced Chronos Deluxe 2.5" 60GB
Win7 x64 Home Premium

I also have a 250 gb and an 80 gb hard drive as well as my DVD drive.

Also, if I decide to add more RAM does it matter very much if I use
one 4 gb stick vs. 2 x 2 gb? I know you're supposed to have matching
pairs for it to run in dual channel mode but how big is the
difference?

thanks for any advice you can give.
Jon

I did a new build recently and ...

* silentpcreview.com is a great site, especially if you want a quiet
machine.

It led me to the Seasonic X-650 power supply, which run fanless below
150watts, a Fractal Design uATX case, which uses 120mm fans along with
sound dampening materials, and the Noctura line of CPU coolers using
140mm fans.

* tomshardware.com for SSD reviews.

I went with a non-SandForce based Crucial 120gb SSD. I should have
gone with a 240gb (and it would've been faster too), but I didn't
think I would fill up half the SSD with applications within a month.

I still cannot believe how quiet the rig is. The loudest noise comes
from the 7200rpm hard drive, which I'm tempted to replace it, since
the other 5400rpm drive is noticably quieter.
 
J

John Doe

Yousuf Khan said:
You refuted nothing, you had nothing else to say, beyond you
saying you refuted it.

You can measure the actual wattage of your current system and
compare that to an online power supply calculator that is intended
to sell overpowered power supplies. That will surprise you. Or,
like Paul said, you can avoid stressing the system. Or, start with
a low-power substitute for the video card.
The online PSU calculators are good tool to get you started, if
you want to buy underpowered PSU's after that, then it's your
choice.

If you ever measure the actual power that your system uses, you'll
be surprised how much less the power consumption is than what an
online power supply calculator tells you. A meter is only $20, why
not?

--
 
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P

Paul

Timothy said:
"Paul" explained:
Timothy said:
"John Doe" > If you want an accurate estimation, spend $20 on a wattage meter.
Online power supply calculators are for selling unnecessarily
high wattage power supplies.
So if one did not possess a power supply of sufficient wattage
to run the system at full power, how does one generate the wattage
that is to be measured by the wattmeter?
[....]
A computer doesn't draw peak power when you start it, boot
it, and sit idle in the desktop. [...]
You can connect the Kill-o-Watt meter, and get a reading from
the meter. Then, try a slightly more stressful program,
and so on. Until either the machine trips out, or the machine
stays up, and you know it can take it.

A modern system in idle, shouldn't use more than about 150W or
so. So you should be able to start it, with a crappy supply.


I think you missed my point, which is: You would need power supplies
in order to decide what power supply to buy. You suggest here to start
with a crappy power supply and work up until the most recently installed
power supply no longer craps out. Or... you could start with a behemoth
power supply and work down. Either way, you have to have one or more
power supplies with which to test. How many of us have access to multiple
power supplies of various wattages with which to test? I think the most
practical thing for builders who don't have a large spare parts bin on which
to draw is to make an estimation and then buy one size larger. The extra
power may be needed someday, and it really doesn't cost appreciably much
more than the one that "just fits". The wattmeter would certainly come in
handy, though, to judge how close to the limit one operates his system.

*TimDaniels*

You'll remember in the OP's post though, he says he currently has
an HX520 and plans to reuse it. So there is a supply to start
with, one rated at 520W, and it's bound to stay up for the initial
power cycle. And then, if you wanted to play with the Kill-o-Watt,
you could.

It's pretty easy to calculate a value in advance. That works.

And if you happened to have a Kill-o-Watt and wanted to experiment,
as long as the idle power of the new system was less than the
limits of your (questionable) power supply, you could play with it
a bit. It wouldn't be my recommended method, but if you want to
try it, you can. It's only if you own a supply of dubious design,
like one of those $20 ones where flames shoot out through the
fan hole, I'd dispense with Kill-o-Watt type experiments in
a case like that. A well designed supply should shut off on
overload.

Paul
 
Y

Yousuf Khan

I went with a non-SandForce based Crucial 120gb SSD. I should have
gone with a 240gb (and it would've been faster too), but I didn't
think I would fill up half the SSD with applications within a month.

You sure that that one isn't a Sandforce-based one? The Sandforce SSD's
are usually the ones that have sizes like 120GB and 240GB, rather than
128GB or 256GB. The Sandforces reserve more of the flash memory to
obtain better wear-leveling.

Yousuf Khan
 
Y

Yousuf Khan

OK, I forgot about the reused power supply. That sounds like a
good starting point for experimentation - just as you suggest.

*TimDaniels*

I recently had to replace my 600W PS because it was causing my optical
drives to fail: I had a couple of DVD burners which both failed at the
same time, I then bought a BR burner, which was showing signs of failing
just like the other two. It was a Zalman 600W, which on-the-face-of-it
is a pretty good brandname. After doing the calculations on the online
PSU calculator, I found it was slightly underpowered, not by much but
still underpowered. So when I went to look for a replacement for it, I
found that the modern PSU's have changed quite a bit since my old one
(bought only in 2008). Back in the old days, PSU's were advertised with
multi-rail 12V outputs. That meant that there were multiple separate 12V
rails, and some went into the motherboard, others went into the video
cards, while others went to everything else. So some rails might be
underpowered while others are just fine. These days all of the better
PSU's seem to be advertising single-rail 12V. The difference is that the
single rail now runs with a higher current than each of the separate
rails of the old PSUs. I think the old PSU's attempted to keep the
individual rail voltages below 19A, but now you can regularly see one
12V rail running over 50A. One rail has less chance of being
underpowered for specific types of connections.

Yousuf Khan
 
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P

Paul

Yousuf said:
I recently had to replace my 600W PS because it was causing my optical
drives to fail: I had a couple of DVD burners which both failed at the
same time, I then bought a BR burner, which was showing signs of failing
just like the other two. It was a Zalman 600W, which on-the-face-of-it
is a pretty good brandname. After doing the calculations on the online
PSU calculator, I found it was slightly underpowered, not by much but
still underpowered. So when I went to look for a replacement for it, I
found that the modern PSU's have changed quite a bit since my old one
(bought only in 2008). Back in the old days, PSU's were advertised with
multi-rail 12V outputs. That meant that there were multiple separate 12V
rails, and some went into the motherboard, others went into the video
cards, while others went to everything else. So some rails might be
underpowered while others are just fine. These days all of the better
PSU's seem to be advertising single-rail 12V. The difference is that the
single rail now runs with a higher current than each of the separate
rails of the old PSUs. I think the old PSU's attempted to keep the
individual rail voltages below 19A, but now you can regularly see one
12V rail running over 50A. One rail has less chance of being
underpowered for specific types of connections.

Yousuf Khan

This is true in some ways, but not others.

A modern supply can be rated for 12V @ 50A. This would be the rating
at the transformer or rectifiers.

But when that ampacity gets to the wiring harness, it might be
dangerous to have that much available. Current limiters
may still be in place.

If you grabbed an arbitrary yellow (12V) wire on the 50A PSU, you'd hope
the design would not allow 49A to be continuously drawn through the
yellow wire. The wire would probably heat to the point of melting and
burning the plastic on the wire.

Instead, you'd hope there is a current limiter, a circuit that monitors
current flow, and limits the current to a value safe for a single yellow
wire (shuts off the supply, if more than that value is drawn).

On an old supply, you might have seen three "12V @ 18A" outputs. They
could have been implemented as a single transformer with three current
limiters. When you see a power supply with a single rail "12V @ 50A",
there may still be current limiters involved, which means the label
on the new supply is hiding a detail. The limit may not be 18A, it
could be a higher number, but there should be a limiter there to
prevent the whole 50A going through one wire. It really all depends on
how much current you can push through a cheap 22 gauge wire.

*True* independent outputs, require separate transformers. When a
few supplies were made like that (there weren't that many of them),
the reviewers took pictures, and you could see completely independent
"islands" on the PCB of the power supply. Such supplies were 1" to 1.5"
longer than regular supplies. That was a hint you were getting the
real deal. When a supply claimed to have independent rails, and yet
managed to do it in a regular sized box, then you knew they were
cheating (because there wouldn't be room for that many transformers).

When it comes to power supplies, deception is all part of the marketing.

This kind of thing, raises the same question about some older supplies.
They made power supplies, where the label said the 5V rail could provide
40 amps. Now, what if one wire on a Molex cable, decided to draw that
40 amps. What does molten plastic smell like, anyway ? :) Too high a
current rating, isn't always such a good idea, if the harness can't
take it. And back in those days, I doubt they would have had current
limiters or monitors in the 5V section.

Paul
 

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