Another "Which PSU?" question (for an older system

FrankDC · Post by **FrankDC** » Tue Apr 05, 2005 1:25 pm

Hi All, I discovered this site a few days ago and it's a wealth of information.. Only now I'm suffering from info overload and am getting confused about what *should be* a basic PSU upgrade. Thanks for taking the time to read through this info and for any suggestions.

I have a 300W SPI supply which has been rock solid for almost six years now. System config was as follows:

Abit BF6 (Slot 1/Intel BX)
P3-S 1.4GHz w/ Slot-T (CuMine > Tullie) adapter
GeForce GF1DDR (no giggling please, I'm not a gamer)
768MB RAM
(3) 36GB Seagate X15's
SCSI CD Burner
IDE DVD/CD Player

Case fans
(2) 16cm .85A chassis fans
(2) 8cm .20A intake fans
(2) 4cm CPU fans
(1) 6cm exhaust fan (rear CPU area)
(1) 8cm exhaust fan (above PSU)

PCI slots maxed out:
29160 SCSI controller
4-port USB2.0 card
Hardware MPEG encoder card
Intel gigabit NIC
Turtle Beach Santa Cruz audio card

Now all of this has been running just fine w/ the 300W Sparkle supply. But recently the fan on my GF1DDR video card went out, and I replaced it with an ATI Radeon 9700 Pro.. And that's when strange things started happening... e.g. occasionally a hard disk will just power down by itself (all three drives have done this, so it's not an individual drive problem). Etc.

I know I must be tapped with all this hardware, fans etc running on a 300W PSU, but I don't know where the major shortage(s) is or are. The current supply is rated at 14A/3.3V, 30A/5V and 12A/12V. What's the most likely culprit for the hard drive problems? PCI and AGP are powered at 3.3V, correct? Why would adding a more powerful video card affect stability of my hard drives (or perhaps the SCSI controller)?

Anyway you can probably tell I'm confused. Any help appreciated!

Elixer · Post by **Elixer** » Tue Apr 05, 2005 2:45 pm

The 9700pro pulls most of its power from the 12V line. This is why it has to have a molex connector plugged into it (well because it draws too much power for the MB alone to supply to necessary power). With 3 hard drives (are they 10000rpm drives?), the 9700pro, two optical drives, a slew of fans, and some power for the processor, ram, motherboard etc, I would say your 12V line is pretty stressed. 12A is not a lot of power nowadays for the 12V line in a power supply. It's also likely that due to 6 years of aging, the capacity of your power supply has dropped somewhat. Something you might try is getting a multimeter and at full load with your hard drives busy defraging or something like that and your video card busy take a measurement of the 12V line. You can do this stright from a molex connector. If this is low, like less than 11.5V, then you've probably found your problem. It also could be the 3.3V line as 14A might not be quite enough for this line as ram and pci cards and the radeon pull from this line. Easiest way to test if your ps is the problem would be to swap in another working power supply and see if this solves the problem. Should this be your problem, almost any of the power supplies on the reccomended list should work as almost all of them have higher amp ratings on the 3.3V and 12V lines, even if the overall rating on the power supply is the same as your current one.

Spod · Post by **Spod** » Wed Apr 06, 2005 12:26 am

Those are 15,000 RPM drives. But Elixer is right - pretty much any current PSU will do. One proviso - if you get a new PSU with a 24-pin power connector, you'll need to make sure it comes with a 24-pin to 20 pin adapter to plug into your current motherboard.

The S12 330W model has enough power for your needs, as you can see on Seasonic's product page. Given that you won't be using much 5V on that system, 3.3V is 20A vs. your 14A, and for 12V you've got 14A to the motherboard, 8A to the molex connectors. Your current supply has only 12A of 12V for everything.

Post by **NeilBlanchard** » Wed Apr 06, 2005 4:51 am

Hello Frank:

Since these folks have already answered your question, all I have to do is say:
Welcome to SPCR!

FrankDC · Post by **FrankDC** » Wed Apr 06, 2005 8:34 pm

Thanks Neil, and all. Great info.

Talz · Post by **Talz** » Thu Apr 07, 2005 10:29 am

One thing, if you buy a power supply with dual 12V rails I believe one rail is exclusive to the 4 pin ATX connector. I'm pretty sure the BF6 does not use this connector, so be careful of this. The power supply might automatically reroute this rail if it's not plugged in, I doubt any manufacturers have bothered with that capability though. Maybe someone can say for sure wether or not this would be an issue but I would be wary of the possibility.

alglove · Post by **alglove** » Thu Apr 07, 2005 11:55 am

Talz wrote:One thing, if you buy a power supply with dual 12V rails I believe one rail is exclusive to the 4 pin ATX connector. I'm pretty sure the BF6 does not use this connector, so be careful of this. The power supply might automatically reroute this rail if it's not plugged in, I doubt any manufacturers have bothered with that capability though. Maybe someone can say for sure wether or not this would be an issue but I would be wary of the possibility.

I have an Enermax power supply with the split +12V rails as you describe, where the +12V2 rail is used by the 4-pin ATX connector exclusively, and the +12V1 rail is shared by everything else. It has been powering an Athlon XP 3000+ on an Epox 8RDA+ motherboard, which has no 4-pin +12V connector. It has been running for a year with no issues.

By the way, there is a chart over at X-bit labs where they measure the power consumption of a 9800 Pro (the closest thing I could find to a 9700 Pro). It seems to draw power from all three rails (+3.3V, +5V, and +12V), with much of it coming from the +5V. However, the +3.3V current is also quite high... in the 4-5 amp range. It is possible that the power supply's "combined +3.3V and +5V" rating could also be an issue here.

http://www.xbitlabs.com/articles/video/ ... ons_8.html

~El~Jefe~ · Post by **~El~Jefe~** » Thu Apr 07, 2005 8:28 pm

Gosh dood,

You have the glory processor on a non glory board. I bet you would do well with more memory bandwidth, it really helps out the tualatin to go from 100 to 133, I felt anyways. I am a big fan of tualatin procs, I always wanted the 1.4 512k cache glory chip myself. Unfortunately, I have the board you want, and you have the chip I want. I have the 1.2 ghz one and latest intel board with every chipset and 4x agp and 133 memory built for tualatin.

I should sell you it. I would love someone to at least have the glory system.
you could even throw over a gig of ram on it. but I wouldnt bother if its just a server with linux?

Another "Which PSU?" question (for an older system

Another "Which PSU?" question (for an older system

Re: Another "Which PSU?" question (for an older sy