|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
88.109.73.30
In Reply to: RE: Current measurements on powersupply P4 pin posted by hfavandepas on April 07, 2009 at 09:07:24
hfavandepas wrote:
. . . your readings are twice as high as my readings.
Sorry, but I don't see how you reach that conclusion. Yesterday, I wrote:
"The current peaked soon after power-up for about 30 seconds at around 1500/1600 ma (though it went off the scale on one occasion), falling by degrees to settle at 330/340 ma when playing.music."
You report readings ranging from 240 to 360 ma. From where I'm sitting, the steady-state (i.e. while playing music) values are pretty much the same.
I repeated the measurements today (I'd left the meter in place.) The steady-state reading has fallen to 320 ma. I'm not getting excited about that - it's a difference of three per cent. (It could be up to 350 ma tomorrow, making it +/- 3%. I'd be delighted if my meter - it's a good one - is accurate to +/- 2% when reading current.)
The 1500 ma peak on a cold restart was still to be seen today, though not for so long. Presumably that's because I'd left the BIOS at clock=140 MHz; Vcore=0.75v. (I wasn't expecting a "Spanish Inquisition".)
You'll see only a short peak if you do a warm restart. To test it properly, you need to store your settings, put the BIOS back to defaults and do a cold start. Then, if you don't get a peak roughly comparable to mine, something funny IS going on.
Whatever, the values you report all lie, give or take, within +/- 100 ma of mine - some are higher, some lower.
(What I didn't report yesterday was that I get a short peak of ~400 ma at the start of each track, presumably as cPlay decodes flac data.)
You don't say what scale you are using (though your data is in amps) or suggest the calibre of your meter. If you are using a 10-amp range, I'd be a little concerned about the accuracy of readings so close to the low end of a low-resolution scale.
You report 0.24 amps running cPlay at 44.1. Are you sure? That's less than three watts - judging by the way it eats batteries, I have a (OK, OK, it's very old) calculator that seems to need more than that.
Seriously, these are very informal "experiments". We have different meters (neither, I'd hazard, recently calibrated) possibly on different scales; neither of us recorded the temperatures of the CPU or the meter or checked how long the device has been running. We are running different software on a different configuration with different target data, etc etc.
I confess I haven't a clue as to how normal manufacturing tolerances might be reflected in crude tests like these.
I just don't see any "Eureka" moments coming from comparing these data - they seem pretty well in line. In short, we can report with reasonable confidence that an under-clocked E7200 chip draws between quarter and half an amp from the P4 line when playing music.
Anything else risks reading into the data what is not there.
Best
Dave
Follow Ups:
Hi Dave,
Lets skip this discussion.
Somehow you feel offended or annoyed if somebody else is posting data that is not inline with yours. You also don’t seem to have any interest if there are other inmates who performed current measurements on the P4 pin.
Every body can read our former posts and draw there own conclusions based on that. Or even better: perform there own current measurements.
LynxL22 dig i/o -> Lavry Black DA10 -> Mogami Gold -> Klein & Hummel O300
hfavandepas wrote:
Somehow you feel offended or annoyed if somebody else is posting data that is not inline with yours.
I'm not offended (or even annoyed) that you did the measurements - this list is short on empirical data. My point was that, on examination, the two "data sets" were in fact pretty much the same and that the differences you claim to have noted were based on (twice) misreading what I'd reported. What's your beef with that?
What did disappoint me was that you seemed to have done the measurements sloppily and then implied that the fault was mine. Why not, instead of throwing a hissy fit, answer my queries?
You also don’t seem to have any interest if there are other inmates who performed current measurements on the P4 pin.
You could be right - what consenting adults do in private with their P4 pins doesn't interest me. However, I did, a while back, report some data for ripple voltages in the context of adding smoothing caps to MoBo power supplies. Bill (Old Listener) pointed out that my figures were way different from those on respected review sites and queried if I had done them properly. I did them again them and found that I had been sloppy - Bill was right and I was wrong. Why don't you try and do the same?
Meantime, skip the abuse.
Dave
Hi Dave,
All I did was mentioning that in past I had read a post on: current measurements on the P4 pin.
I wrote:
“ In some posts I saw measurements of the current on the P4 pin of about 0.7 amp when working. And 1 amp during boot and startup. I found these mentioned currents very high. So I measured them myself. “
I did this by heart. But my memory wasn’t far off.
Your post:
Posted by Ryelands on December 27, 2008 at 11:06:42
………..
Incidentally, it also makes it easy (ish) directly to measure the CPU’s current draw, something I’ve never seen reported (though I’m sure it’s done often enough). So far, I’ve measured it only briefly and only on the 65nm Biostar board.
I had assumed it would vary wildly but it was surprisingly stable: an E1200 processor drew 1.4 amps on power-up and during POST but, as the OS loaded, it dropped to and stayed at between 0.7 and 0.8 amps and rose again by about 100 milliamps when running cPlay (without upsampling).
………..
Since I found these mentioned currents very high (for my Gibabyte GA-G31M-S2L mobo + E7200 processor), I decided to measure the currents on my P4 pin myself and also post the results on this forum.
So owners of a Biostar board + E1200 processor can use your readings.
And owners of a GA-G31M-S2L + E7200 processor can use my readings.
No more, no less.
After that you jump on me with pretty strong language and lengthy discussions on a wide variety of topics. The rest one can read in the former episodes of this post.
I now consider this case / post closed.
LynxL22 dig i/o -> Lavry Black DA10 -> Mogami Gold -> Klein & Hummel O300
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: