i5 power supply question

I have a photog buddy that wants to upgrade his system to an i5....but I'm trying to figure out whether he's going to need a new PSU. Currently, he has a 450W Antec that's almost 3 years old. He's not into o/c-ing and thinks he wants to keep his 18-month old GDDR3 vid card for now.

So I think the idea is (after talking it over with him)....

Upgrade now: cpu + mobo + mem
Upgrade later (i.e. 6-12 months from now): vid card + psu

However....my question is: Do the i5/mobo combos require something that a 3-year old PSU wouldn't have? Is 450W enough get him by until he upgrades his vid later next year? I've searched a few places, but can't seem to find anything conclusive. Maybe I'm not looking in the right place!

Thanks in advance.

I have been wondering the same thing.

Due to a restricted budget, I am considering playing it safe and stopping short of an expensive i5 upgrade (DDR3 required; the boards are a bit expensive at the moment; my PSU could be very marginal) and going for a decent Core 2 Duo instead. Cheaper all round and less power consumption (and less heat, I expect). I use a Prescott P4, so it would still be a fairly big improvement.

I looked at four different PSU calculators on the net and got four different answers. Some suggested that 450w would not be enough, yet others suggested that it would still be plenty. Your friend's results could vary just as wildly. There is no particular compatibility issue, though, as far as I'm aware. The power connectors have remained unchanged for a while now, but that is something that can be confirmed by checking specs on the relevant motherboard manufacturer's website and comparing that to the existing PSU.

What spec does your friend currently use?

As long as the PSU has the 24pin (or 20+4) main plug and a 4/8 pin CPU plug it should work fine. I don't recall anything special about my Corsair 650TX that is "i7 compatible" other than the two things mentioned above.

In regards to your power supply question, I would check the motherboard manufacturer specs. They should have a well defined spec that details the requirements of the power supply. Intel® Desktop Boards support the following power supply specifications:

ATX12V version 2.0
SFX12V version 3.0
TFX12V version 2.0

I think 450W might be a little on the low side, in terms of power, but there are other variables that are just as important.

Regards,

110yd

In2Photos wrote in post #9080851
As long as the PSU has the 24pin (or 20+4) main plug and a 4/8 pin CPU plug it should work fine.

Thanks, that's what I thought....but just double checking (as I haven't yet built an i5/i7 system yet). And, yes, his ps should have the 24 and 4/8 plugs.

Ade H wrote in post #9080310
I have been wondering the same thing.

Due to a restricted budget, I am considering playing it safe and stopping short of an expensive i5 upgrade (DDR3 required; the boards are a bit expensive at the moment; my PSU could be very marginal) and going for a decent Core 2 Duo instead. ?

Look at a Core 2 Quad instead. Twice the performance of a Core 2 Duo, but a Q8300 costs about the same.

BeritOlam wrote in post #9081353
Thanks, that's what I thought....but just double checking (as I haven't yet built an i5/i7 system yet). And, yes, his ps should have the 24 and 4/8 plugs.

Quoted wattage is not the problem, it is efficiency and quality of the power supply you need to worry about.

Since you going to replace everything else with high quality parts, it makes good sense to spend a little bit extra and put in a good quality power supply as well.
The old one might work, but you don't know. You also don't know what sort of condition it is in, or how much longer it could last.
Currently it's an unknown quantity, best practice says replace it with something you know will work.

110yd wrote in post #9081316
In regards to your power supply question, I would check the motherboard manufacturer specs. They should have a well defined spec that details the requirements of the power supply. Intel® Desktop Boards support the following power supply specifications:

ATX12V version 2.0
SFX12V version 3.0
TFX12V version 2.0

I think 450W might be a little on the low side, in terms of power, but there are other variables that are just as important.

Regards,
110yd

I'm trying to remember what we bought for him back in 2006, but I'm nearly positive it would have been ATX12V 2.0.

I know 450W is a little on "the low side" these days. I've tried to do the math myself (i5 + mobo + 2+2gb RAM + average vid card + 2 DVD drives + 2 SATA drives)....and 450W would appear to be enough.

But....just looking for other's opinions.

Moppie wrote in post #9082296
Quoted wattage is not the problem, it is efficiency and quality of the power supply you need to worry about....Currently it's an unknown quantity, best practice says replace it with something you know will work.

Actually, I did mention it was an Antec 450W PS in my OP. It may not be the Mercedes Benz of PSU's....but I've had good results with Antec. I have a 4-year old one running my Ubuntu box right now -- checked it out recently, and it's doing just fine. Granted it's not pushing near as this one will....but the rails seem solid.

But your point is noted. Ideally, I'd agree with you (i.e. get a new PSU with the system upgrade)....and I suggested it already (and I'll probably do so again ). However, said individual is wondering if he can wait 6-12 months when the cash flow is better, when the more powerful video upgrade comes. That's why I was curious what people thought.

BeritOlam wrote in post #9082381
I'm trying to remember what we bought for him back in 2006, but I'm nearly positive it would have been ATX12V 2.0.

I know 450W is a little on "the low side" these days. I've tried to do the math myself (i5 + mobo + 2+2gb RAM + average vid card + 2 DVD drives + 2 SATA drives)....and 450W would appear to be enough.

But....just looking for other's opinions.

Here is a link to information from an Intel spec. I would take a careful look at this document and adjust accordingly. Page 52 http://downloadmirror.​intel.com …g/DP55WB_TechPr​odSpec.pdf
+++++++++++++
For example, for a system consisting of a supported 95 W processor (see Section 1.4 on page 14 for a list of supported processors), 1 GB DDR3 RAM, one high end video card, one hard disk drive, one optical drive, and all board peripherals enabled, the minimum recommended power supply is 460 W. Table 24 lists the recommended power supply current values.
+++++++++++++
Regards,
110yd

110yd wrote in post #9082583
Here is a link to information from an Intel spec. I would take a careful look at this document and adjust accordingly. Page 52 http://downloadmirror.​intel.com …g/DP55WB_TechPr​odSpec.pdf
+++++++++++++
For example, for a system consisting of a supported 95 W processor (see Section 1.4 on page 14 for a list of supported processors), 1 GB DDR3 RAM, one high end video card, one hard disk drive, one optical drive, and all board peripherals enabled, the minimum recommended power supply is 460 W. Table 24 lists the recommended power supply current values.
+++++++++++++
Regards,
110yd

Thanks. That's more the kind of specs I was looking for.

I checked a couple sites like this:
http://extreme.outervi​sion.com/PSUEngine

The problem is they don't spit out the same results....and they are considerably less than what Intel recommends in the above. So it makes me wonder how 'inflated' Intel puts that number just to be safe -- I know they've done so in the past.

Also, I've always *assumed* the guys pushing 500+ watts were doing so primarily to (a) run high-end video card(s) and (b) do some serious o/c-ing.

BeritOlam wrote in post #9083320
Thanks. That's more the kind of specs I was looking for.

I checked a couple sites like this:
http://extreme.outervi​sion.com/PSUEngine

The problem is they don't spit out the same results....and they are considerably less than what Intel recommends in the above. So it makes me wonder how 'inflated' Intel puts that number just to be safe -- I know they've done so in the past.

Also, I've always *assumed* the guys pushing 500+ watts were doing so primarily to (a) run high-end video card(s) and (b) do some serious o/c-ing.

I'm running a Corsair 650TX in my machine. i7 920 stock speed, 6GB RAM, 2 SATA HDD, 2 SATA DVD Drives, ATI 3450 GPU. I went "big" so that it doesn't have to work as hard. Keeps the fan at a slower speed for noise. I wouldn't go any lower on a workhorse machine. Newegg is running some black friday deals already. You may want to check them out. I picked up a WD 1.5TB Green drive with a free SATA to USB Dock for $90.

Moppie wrote in post #9082296
Look at a Core 2 Quad instead. Twice the performance of a Core 2 Duo, but a Q8300 costs about the same.

Quoted wattage is not the problem, it is efficiency and quality of the power supply you need to worry about.

Since you going to replace everything else with high quality parts, it makes good sense to spend a little bit extra and put in a good quality power supply as well.
The old one might work, but you don't know. You also don't know what sort of condition it is in, or how much longer it could last.
Currently it's an unknown quantity, best practice says replace it with something you know will work.

newegg has a special on q8300, $134 is a sweet deal no matter who you are.

i5 is about 10-50% faster than a similarly clocked core 2 quad core thanks to turboboost (especially for single threaded apps), and actually only uses about the same amount of power idle and in use. a 450W PSU is sufficient if you are looking at very low power graphics cards, but if you are going with something like a gtx 260 or the ati 5750, get a 700-750W minimum.

Don't forget that when the old power supply was designed and built, it would have only been intended for use in a Core 2 Duo at the most.
An i5 is several generations of technology away from a Core 2.

basroil wrote in post #9084036
newegg has a special on q8300, $134 is a sweet deal no matter who you are.

I'm looking at the price of Q9550's at the moment. They are currently cheaper than my Q6600 was.

Well, for what it's worth, my old system (mobo, specifically) died a couple weeks ago and I put a new i5 system together. Here's what I'm running -

Asus P7P55D Pro
Intel i5 750
4 x 2GB DDR3 1600MHz (G. Skill)
ATI Radeon 5770
DVD-ROM
DVD-RW
1 x WD 150GB (Raptor; 10,000rpm)
2 x WD 750GB (7200rpm)
1 x external (via eSATA) WD 1TB (powered separately)
SoundBlaster X-Fi Gamer
Too many miscellaneous USB devices -
Intuos tablet
cardreader
wireless headset
etc.
Windows 7 x64 Ultimate

I don't really overclock - it's not my thing. The only thing I do is that I wanted to run the RAM at full speed (1600MHz), which means you have to run that FSB at 160MHz.
Native settings for the i5 750 is 133MHz FSB x 20 cycles = 2.67GHz
Instead I run at 160MHz x 17 cycles = 2.72GHz
The Asus motherboard manages all that for you when you tell it to check the XMP settings on the RAM.
So I'd say that's pretty insignificant over-clocking..

But I digress....

The point is I'm running all that on my "old" (probably 2 1/2 years) Corsair 520W modular power supply.

I definitely had the same worries as you and wondered if I should upgrade to the Corsair 750W power supply.

When I first got everything running I started having crashes where the screen would turn weird wavy colors and then the system would restart. Of course I worried it was the powersupply. What was weird though was that it was fine when I was playing a 3D game (which of course would task the CPU & video card the most, therefore use the most power) - it would do it when I was just surfing the web and doing e-mail, which should be using 5% of the available resources. Then I did some reading and it seemed to be a problem a lot of people with the ATI 5770's were having. So I RMA'ed it and got a different one (different brand too, even though they're all basically the same ATI reference board) and since then, no issues. *Knock on wood*

I still wonder about it cause you're probably like me and want to KNOW if you need more and not just guess... Is my 520W supply pushing at 100% and just barely making it? I don't know. I wish there were some kind of real-time power analyzer for them that would show statistics as to how much capacity it's using so that you know if it's running at 100% and you need a bigger one...

I guess I'm gonna see if it stays stable for a couple weeks and if so, not worry about it.
If I get any weird crashes or anything, I might just ask for the 750W'er for Christmas just for piece of mind...

Not sure if that helps, but there you go...

Moppie wrote in post #9084135
Don't forget that when the old power supply was designed and built, it would have only been intended for use in a Core 2 Duo at the most.
An i5 is several generations of technology away from a Core 2.

I'm looking at the price of Q9550's at the moment. They are currently cheaper than my Q6600 was.

q9550 is more expensive than an i5 though (even taking into account mobo prices. And as for the power supply, the motherboard takes care of the smoothing out the power better in the i7/i5 mobos than it did in quad cores. even a three year old PSU should be more than fine.