Greetings.
I'd like to start by thanking all the great reviewers on JG for your thoroughly entertaining and passionate reviews. Please, never stop.
If someone could please help figure out this weird issue, t'would be much appreciated.
So, specs wise I have a 4 year old Silverstone OP700, powering the following 24x7:
- Gigabyte GA-EP45-UD3 motherboard (30W-40W?)
- C2D E8400 OC'd to 3.74 Ghz (65W TDP + a bit more?)
- 2x 2GB DDR2 RAM
- Geforce 9800 GTX (140W Max)
- Basic 4 Port RAID PCI card
- 9x 3.5" hard drives
- 7 fans (excluding PSU and Video card) - 4x120mm (7W each) 2x140mm (4-5W each), 1x80mm.
- 48W 4 channel fan controller for the 4x120s.
- Creative 5.1 soundcard
- LG DVDRW drive (IDE)
Almost always, 3 of the 4 120mm fans are intentionally off at startup (1 is for CPU) to reduce draw, and then turned on 10 seconds later.
So, this problem has been occuring for close to 2 years now:
If there are 8 or more hard drives running, exactly every 20 seconds, any media that plays, regardless of format, has a very slight hickup/skip in the sound.
Video isn't affected and neither is mouse movement or anything else, it never causes a BSOD either, (it usually takes 2 days max before I get tired of the skipping). For 4+ years now it still gives 90+ days of uptime with no problems other than windows being a bit sluggish.
If I unplug 2 of the 9 hard drives, things are fine.
Please correct me if I'm wrong but this could possibly be caused by drawing too much power with more than 7 hard drives - but what could be occurring every 20 seconds in a PSU to cause the sound glitch?
Reading JG's review of the OP650, it's not a bad PSU, so I'd expect the 700W to hopefully be in roughly the same class:
http://www.jonnyguru.com/modules.php...=Story&reid=39
Assuming, worst case scenario that each hard drive takes 3x their operating wattage (10W) to spin up, so around 30W, 9 hard drives would draw a max of 270W at spin up and then, assuming they can't idle, would soon drop down to 90W. But a relatively instant 270W draw should just be a slap in the face for a 700W PSU and not a knockout uppercut.. Right?
Although for clarification, if someone could please advise if the startup power draw from hard drives is all drawn from the 12V rail or a 5V rail or a combination of the two, that would be helpful in understanding things.
Also, it makes no difference whether the RAID card is used or not, as there are 8 SATA ports on the motherboard - and there's no staggering feature on either of them.
Applying the same rule to all of the fans, spinning up would probably be a bit over 110W, and then drop to around 40W. (So with drives and fans we're up to around 400W?)
I read on the Backblaze blog (they build storage based racks), that the 5V rail is what hard drives typically demand the most power from, so having a high wattage on that is important when running lots of them.
Another thing I noticed was that the OP700 has quite a generous +5V max wattage, even compared to some 1000W+ PSUs:
OP700:
+3.3V +5V +12V +5VSB -12V -5V
Max.(Amps) 24A 30A 58A 4.0A 0.5A /
Min.(Amps) 0A 1A 3A 0.1A 0A /
Range (%) +/-3% +/-3% +/-3% +/-5% +/-10% /
combined +3.3, +5V 180W
combined +12V 696W/ 58A
So that brings me to wondering what the flying puck is causing the sound glitch..
Any ideas?![]()