How Much Power is Enough for THIS

[gamerbuilder2004]

Ok, so I posted earlier regarding this same computer and you guys really helped me out. Thanks a lot! Now I need to solve the original problem. I got this mondo-cheapo case that came with a "LeadPower" power supply. Supposedly a UL certified 550 W PSU. Well the computer needs to run 4 7200 RPM HDs, several case fans, a 3.2 Prescott core P4, a GeForce 5600, 4 GB RAM, a floppy, and 2 optical drives. Well anyhow, 550 watts should be WAY more than enough, but this thing is so cheap the whole computer shuts down after under a second if more than a single drive is connected to it. Apparently it's hold under a load is really bad. I'm getting an Antec (or another brand if recommended). I really think 430 should be enough. Some other guys said it ran a similar setup all right. Opinions?

Thanks a lot!

 

[UsandThem]

I would go with a 480w or 550w. I would lean more towards an Antec 550w.

 

[amdskip]

Antec 550w will cover any future upgrades you do.

 

[mechBgon]

Antecs are good. You might also look at Enermax since they do usually have lots of 12V current and also a lot of standard 4-pin drive plugs (assuming your drives aren't SATA drives). Whatever you get, yeah, you want a quality brand. I wouldn't even tempt fate any further with the cheapie one, just take it out.

 

[Badut78]

Aside from the capacity of the PSU, you might also want to consider the amount of current it can supply on each rail 3.3V, 5V and 12V
Perhaps do an inventory of your devices and see how much current they need on each rail, add them up and make sure the PSU you get supplies enough current.

 

[Polishwonder74]

<== Uses an Antec 480 True Blue. Check the siggeh for specs.

I lost a hard drive (probably from undervoltages) when I was using an Enermax 350 Watt. That's when I bit the bullet and dropped a massive wad of cash on this big nasty 480. I'd be pretty weary of that K-Mart brand power supply, it'll peak at 550, but the sustainable wattage will fall way short of 550. Plus brownouts, vacuum cleaners and 'fridges clicking on might wear it down quickly and those K-Mart brand power supplies don't have a very good track record of saving your computer when disaster strikes.

Hope this helps you, good luck.

 

[LiLithTecH]

What is putting it over the top is the 4GB RAM.

P4 Prescott = 80w
CPU fan = 3w
4 HD's = 115w
MB w/on-board devices = 25w
4GB ram = 240w (could be more depending on module brand)
Video = 20w
2 System fans = 6w
2 Optical drives = 25w
Floppy drive = 5w

Total = 519w

General Rule is CPU + 80% of components


80 + 351 = 431w minimum required PSU

 

[dclive]

Originally posted by: LiLithTecH
What is putting it over the top is the 4GB RAM.

4 HD's = 115w
4GB ram = 240w (could be more depending on module brand)
2 Optical drives = 25w
Floppy drive = 5w

Just out of curiosity, what sort of reference information is out there that suggests this information? I'm particularly interested in the RAM amount.

(Please, not a power supply seller's website.)

 

[mechBgon]

Originally posted by: LiLithTecH
What is putting it over the top is the 4GB RAM.

P4 Prescott = 80w
CPU fan = 3w
4 HD's = 115w
MB w/on-board devices = 25w
4GB ram = 240w (could be more depending on module brand)
Video = 20w
2 System fans = 6w
2 Optical drives = 25w
Floppy drive = 5w

Total = 519w

General Rule is CPU + 80% of components


80 + 351 = 431w minimum required PSU

As an academic point... some of those numbers seem off. Prescott 3.2's have a "cruise" wattage of 103W with absolute peak being rated as 4/3 of that (by Intel's scheme). The last time I bothered to look up a double-sided Micron module in Micron's PDF documentation, they had an absolute peak of 15W power draw per module. My 15k SCSI drives have sustained max power draws of about 10W and 12W respectively (although they do take some extra to get rolling, but they start as their IDs are polled so they're offset a bit).

 

[LiLithTecH]

Originally posted by: dclive

Just out of curiosity, what sort of reference information is out there that suggests this information? I'm particularly interested in the RAM amount.

(Please, not a power supply seller's website.)

Manufacturer specs are available and what I quote from.
As a rule, RAM consumes 10w per 128mb (depending on chip type\configuration).

AMD has builder guides available on their website. INTEL requires multiple requests (and being a vendor helps)


mechBgon:

The P4 Prescott is quoted at estimated avg usage (INTEL specs. No they are not on their website).
Stepping rate, strength of clock frequency, if thermal monitor throttling is enabled/disabled, all play
a part in averaging. (website posts P4 Prescott 3.0 @103w Thermal).

SCSI is not IDE. Quoted for such.

Some specs can be higher, some lower, with many variables which is why I usually post averages.

 

[mechBgon]

I think it's time for a reality check. You're saying each module can draw 60W? Wrap your hand around a 60W lightbulb for 10 seconds, then ground yourself and feel a 1GB DIMM under heavy load with the other hand (the one that you didn't burn on the 60W lightbulb ). Notice a difference? I looked again at Micron's tech documentation, and I'm sticking with my ~15W/module for a Prescott-compatible 16- or 18-device DDR400 DIMM.

I also verified the typical and peak specs on a 200GB ATA drive. The fluid-bearing motors can draw a lot of 12V power at startup (Seagate says 2.8A maximum), but they don't sustain that... seek/read/write wattage for a running Seagate 7200.7 200GB drive is 12W. All the same, yeah, they could present a challenge trying to get four of them rolling at a time, so I'll grant your HDD power numbers as a transitory condition. Along with the Prescott's appetite, it would be another good reason to shop for a PSU with healthy 12V amperage.

 

[VirtualLarry]

Originally posted by: mechBgon

Originally posted by: LiLithTecH
What is putting it over the top is the 4GB RAM.

P4 Prescott = 80w
CPU fan = 3w
4 HD's = 115w
MB w/on-board devices = 25w
4GB ram = 240w (could be more depending on module brand)
General Rule is CPU + 80% of components
80 + 351 = 431w minimum required PSU

As an academic point... some of those numbers seem off. Prescott 3.2's have a "cruise" wattage of 103W with absolute peak being rated as 4/3 of that (by Intel's scheme). The last time I bothered to look up a double-sided Micron module in Micron's PDF documentation, they had an absolute peak of 15W power draw per module. My 15k SCSI drives have sustained max power draws of about 10W and 12W respectively (although they do take some extra to get rolling, but they start as their IDs are polled so they're offset a bit).

I'm with you, I was going to say "15W" per module, as a good rule-of-thumb these days, even before I read your paragraph. There's no way in heck that the DRAM array is dissipating 240W of power, that would fry the mobo and melt the insulation of the wires around there in no short order.

Think about it - CPU is actively cooled, with a heatsink and fan, and it is drawing (at most) 105W (for an evilly-hot Prescott PIV chip, my AMD XP is closer to half that). Yet the DRAM array is itself passively-cooled, no massive PII-style heatsinks affixed to the DIMMs, no "DRAM array cooling fans", nothing.

Which makes more sense? Hmm.

 

[gamerbuilder2004]

I've read about utilities to stagger the initial spinning up of the drives so that all four don't startup at once. Have any of you heard of anything like this? It seems like it would have to be integrated into the BIOS. Or possibly even in the BIOS of the RAID card.

 

[Gamingphreek]

1. OCZ Powerstream
2. Enermax (any type)
3. Antec
4. Zalman, Silverstone, etc.

-Kevin