Typical mains power for mid-range PC?

On Mon, 31 Jul 2006 13:09:22 +1000, "Rod Speed" Gave us:

Designs vary, dumbfuck.

On Mon, 31 Jul 2006 13:09:22 +1000, "Rod Speed" Gave us:

You are the only "it" participating in this thread, dumbfuck.

"Phat Bytestard" wrote

Meaning a chip?

So, what's the upper limit to allow a HD to get to if running a hot one in a less than greatly ventilated location?

I've been thinking of getting a newer one.

Thanks much!

"Phat Bytestard" wrote

I guess you know I was referring to the HD at 20's and 30's.

Yes, the AMD's have been really nice. My Winchester is idling at 27C. It's overclocked to 2400 at 1.45v.

On Sun, 30 Jul 2006 22:39:01 -0700, "Ed Light" Gave us:

External drive enclosures typically have no forced air cooling, relying only on vent holes in the case. They even have small power supplies in them.

I have seen drives so hot it is hard to keep a fingertip on them for an extended period operate for years without a problem. Even in rough environments.

By the same token, I have seen a hot case cause a hard drive failure.

Since Seagate was the primary company contracted by the mil boys for rough service applications, I have bought that brand for years, but have also bought IBM (now Hitachi) and WD drives too.

Have not had much luck with MaxTurd though.

But that is just me.

Phat Bytestard wrote

Even you cant actually be THAT stupid.

Nope.

Wrong, as always.

On Sun, 30 Jul 2006 22:49:28 -0700, "Ed Light" Gave us:

Perhaps, but many boxes are atypical these days. Mine has four drives in it, one at 10k RPM, and two optical disc readers, a floppy...

I'd like to think it only uses 115W at idle, but I think it is more like 150W. It would be cool to get a reliable, accurate AC watt meter to check it out.

I use a 500 Watt PS. I'd like to think it runs cooler being barely taxed than running a 250W drive (if you can even find one) taxed at nearly its rated capacity.

I would suggest that all perform this simple operation of not responding to this immature dolt known here in Usenet as "Rod Speed".

The only thing he has been speedy about is an incorrect answer to all challenges.

I am done with you, boy.

"Phat Bytestard" wrote

Here's what silentpcreview.com has to say on p.3 of *Power Supply Fundamentals & Recommendations*:

so, Is Higher Power Better?

Without getting into technical details, the nature of a switching power supply is that it delivers as much power as is demanded by the components. This means that when installed in a PC whose components require 200W, a 400W PSU and a 250W PSU will each deliver 200W. Does this mean the 400W is coasting while the 250W is struggling? Not if they are both rated honestly and if they have the same efficiency. If one has lower efficiency than the other, then it will consume more AC to deliver the same power to the components, and in the process, generate more heat within itself. As long as there is adequate power, higher efficiency is the key to cooler, quieter PSU operation.

The main benefit of higher power PSUs is when the airflow in the PSU is deliberately set very low in order to minimize noise. This usually means the PSU components will run hotter. If all other things are equal, a higher rated PSU may be a better choice in such an application because its parts are generally rated for higher current and heat than a lower rated model.

On Sun, 30 Jul 2006 23:06:27 -0700, "Ed Light" Gave us:

I worked designing switchers for the last nine years. I don't really need a primer.

That has never been dispute. If you read what I wrote, you would see that the question was about efficiency. The 250 W supply pushing

200 W surely delivers only 200W as demanded by the load. The question is, does it run hotter in doing so?

The 500W supply delivers only 200W to a 200W load as well, but may be a lot more "comfortable" in doing so.

I can practically guarantee that the ripple on each supply rail will be lower on the bigger supply.

Sure it does. As one approaches the rated capacity of a switcher, the rated ripple voltages are going to be seen by the load (your PC). In the case of PCs, that can be a bad thing.

No shit. Basic math.

Who give a shit about fan noise? I am more concerned that the DC being supplied to my PC is, in fact, DC, and not some electrically noisy, high ripple psuedo-DC. With a cheap Chinese low wattage supply, you can count on the latter.

Again, mechanical noise means nothing to me.

I doubt that my thermally monitored, high end PC supply runs hotter than a cheap chinese OEM supply. Quite the opposite, in fact.

They typically also supply a much quieter (ELECTRICALLY) DC source.

With a modern PC that has very low voltages utilized in it, this is a MAJOR issue.

Remeber the old addage... You get what you pay for.

[snip]

I have always wondered about the rubber sleeve which goes over almost all of my old Seagate U6.

The drive can get quite warm and that rubber must make it worse.

Was the rubber there just for physical protection? Presumably for the electronics (rather than the metal plate on the opposite side)?

Are there any disadvantages if I want to improve cooling by removing this rubber sleeve?

Was Seagate producing the same drives for military apps as for civilian or was Seagate producing a whole separate product line?

On Mon, 31 Jul 2006 08:15:32 +0100, Jon D Gave us:

Not at all. The drive case, and the lid are never far off each other temperature wise.

Even though the main heat source is the spindle motor, said heat heats up the air in the platter box, and subsequently, the lid.

Both the case (platter box) as well as the lid give off a certain degree of infra-red energy to the locale air. Having air move over the drive carries of that hot air, and the process continues. This is convection cooling.

Fins would be nice, but it was found that a "hot" drive is such a typical scenario for the operating environ of the device that the design should center around an elevated ambient norm. So smooth is just fine, and dissipates plenty of heat. Having the lid and case as thermally separate elements will make little or no difference.

Second to the heat generated by the spindle drive is the circuit board that contains the electronics that drive the spindle motor and the read/write MR head array. Most drives these days have all the electronics on one PCB (not counting inside the drive on the head arms), so included on said driver board would also be the digital I/O electronics. I've had older drives that had two huge 5.25 x 6.5 inch PCBs stacked on the bottom, and a 5.25 by 2 inch PCB on the back. Electronics has come a long way.

It is there for vibration isolation, which in turn yields a mechanically quieter drive.

A drum (the musical device), when struck, will produce more noise with the head attached to the resonating cavity better than one with the head mounted on rubber gaskets. With a drum, the difference is less, but the idea comes across.

A hard drive with a separate, non intimately contacting lid, will be quieter when operating as the head seek noises will not couple to the lid as well, which would produce a drum like effect.

Unsure what you mean, but The PCB assembly on the "bottom" of the drive is typically elevated from the platter cavity/drive case, both physically suspended, and thermally isolated... usually.

Nowadays, they are making PCBs that conduct heat right through the PCB much better than in days of the past, so conductively cooled designs may exist, but coupling to the drive case would be madness since it operates at a higher temperature than the desired (and achieved) operating temps of the driver/I/O PCB assemblies.

The air passing over a drive cools the entire drive, but is primarily needed to cool the PCB assembly as it radiates to the air less than the huge surface of the drive case, and has a number of discreet components on it which need to have their generated heat dissipated. They radiate to the air, and it gets carried off by the air flow.

If the case temps these days were a problem, drive makers would be making matte finish cases to help abate the heat, by radiating IR better off the drive. Since they paint them up glossy, I'd say that they have achieved the mean temperature they want the drive to run at, at the mean external ambient they declare in their specs. Typically 72 F.

You should not mess with your hard drive.

"Phat Bytestard" wrote

The low wattage psu's they are talking about are active pfc, expensive, very efficient, lots of amps on the 12v.

For instance, the Seasonic S12 330 has 22 amps on the 12v, if you count the

1 and 2 lines together, since they're coming off a single 12v supply.

It may be more efficient at typical pc wattages than a more powerful psu.

On Mon, 31 Jul 2006 08:24:42 +0100, Jon D Gave us:

No. The drives they engineered were the state of the art, and Joe Blow VAR got the same gear that the gov got. Makers didn't have a lot of time to make multiple designs. One recount from that would be to say that they MAY have had the drive maker use all mil parts, likely quadrupling the cost of purchase, but I'd say that hard drives were likely one of the first critical pieces of gear the mil boys bought that didn't go through the rigors of mil standard manufacturing processes. This would have been literally years before COTS ever hit the scene.

A lot of technologies advanced as a result of hard drive technology.

The main differences between mil and consumer was in the design of the carriages and other such equipment which these system components were being integrated into.

For instance, at 70,000 feet in the air, the atmosphere is quite thin, and pressurized cabins are NOT held at one atmosphere.

One either has to pass A LOT more air over a heat sink or make the design such that conductive cooling methods can be utilized to carry heat from operating systems.

Hard drives have been one of the most intensively "kept in the design channel" as any device can be. They had to stay "state of the art" at all times. Both mil as well as corporate IT admins tried to stay right on the curl of that wave.

They have caused advances in chip design, motor design, motor controller design, magneto-resistive head design. This is due to the fact that it is truly the most important piece of equipment in ones computer system. Then and now in the final analysis.

Today, however, we have storage subsystems that exist outside the computer case, and that is actually safer for the drive lifespan, albeit less safe from a data security POV.

I think the HD at LANL that was found behind the drinking fountain was an internal 3.5 inch drive, so it required actual removal. from a case. So much for my previous statement. :-]

On Mon, 31 Jul 2006 01:40:13 -0700, "Ed Light" Gave us:

That adds up to more than 250W for the 12V alone, and PC supplies typically have a high current +5 Volt rail, not the 12V.

Also, a 250W supply has to supply all the voltages at the rated power. Most cannot actually produce what they rate on each channel (rail) with each fully loaded to their "rated capacity". The ripple goes through the roof.

So, there is NO 250W supply that supplies 22 amps to the 12 Volt rail. That is already beyond the output rating.

The reason the 500W supply is better is due to the fact that under said lighter loading (250W), it will indeed also have a lower ripple voltage on each of those rails. Lower still at the expected "average PC" consumption level. I guarantee it, in fact. Unless it is some shit copied design. A re-do of a switcher requires a full re-characterization and tuning of the supply for peak efficiency and clean stable operation. That means that any chinese knock off copy of even a good design is not going to function the same without said characterization and tuning routines.

Our LV switcher supplies were five times quieter than any competitor, even OVER their rated spec for power, and I am referring to electrical noise and clean operation.

Our standard HV supplies were ten times quieter than the nearest competitor. Some were even far better than that. I had supplies tuned to 0.000007% ripple, and 0.000033% regulation.

That equates to 10 mV ripple and 0.5V regulation on a 1500 Volt rail out to 250W at 17kHz. Think of me on your next modern, hightech CAT scan. All those detectors arrayed around you in that ring are fed the cleanest voltages on the planet. This makes for the best CAT imagery on the planet.

An X-ray exciter makes a cleaner flux if the excitation electron stream is clean. This cleaner X-ray flux makes a higher contrast ratio image. Think of me when you think about how safe your natural gas lines are or your Nukes, or your airport baggage examining stations.

You would possibly prefer that I did not. My thoughts about airport baggage scanners tend to be based on places like a Rome airport, and many more, where the examiners were, if there at all, far to busy chatting to each other than to actually look at the output of no doubt excellent technology.

Hopefully the gas lines are better - but ISTR something about 3 Mile Island and weld inspections?

I fear that the most common source of failure for any system, PCs included, remains in the neural network controlling it..

On Mon, 31 Jul 2006 10:19:22 +0100, Palindr?me Gave us:

Perhaps lack thereof.

"Phat Bytestard" wrote

12v is big these days for cpus and video cards.