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Computer: CPU
CPU Activity Light   (+10, -2)  [vote for, against]
analog indicators for what is going on inside your PC

You have a little LED to tell you when your Hard Drive is being accessed. I would like to have other lights that would flicker when the CPU is being used. Maybe hook some lights up to the bus or the registers or the memory also. Ideally you could have a whole bunch of lights flashing all the time.

The practical reason for doing this would be so you could tell the difference between when your PC is locked up completely and when it is has so much to do it can't keep up. This would be a more direct indicator than using any CPU monitoring software.

I imagine the problem would have to be in the amount of power you would have to draw in order to make the light light up is much greater than the amount of power that you are checking for (i.e. the signal on the bus)
-- blahginger, Aug 18 2000

LED Meter http://www.ewal.net/ledmeter.shtml
Build your own and use it for CPU load (or whatever else)... [egnor, Aug 18 2000, last modified Oct 04 2004]

led_cpu http://www.cs.auc.dk/~borg/led/
"led_cpu is a small and usefull [sic] package to show the CPU load on your keyboard leds." [egnor, Aug 18 2000, last modified Oct 04 2004]

Matrix Orbital http://www.matrix-orbital.com/
Maker of blinkenlight add-ons for PC hardware. Easy to hook up to a load meter or anything else (CPU temperature, etc). [egnor, Aug 18 2000, last modified Oct 04 2004]

Blinkenlights http://www.tuxedo.o.../blinkenlights.html
Etymology of them blinkenlights [hippo, Aug 18 2000, last modified Oct 04 2004]

www.blinkenlights.com http://www.blinkenlights.com/
This is a pretty interesting site. [hippo, Aug 18 2000, last modified Oct 04 2004]

[Zero0116]'s link http://casemods.poi...eturn.org/cpumeter/
[phoenix, Mar 18 2002, last modified Oct 04 2004]

LED Meter http://ewal.net/_led.aspx
[edwalter, Oct 04 2004]

The original BeBox had such lights. I had one of the first PPC603 66MHz x2 boxen and then upgraded it to the PPC603 133MHz x2. Both had a set of LED's which showed processor utilization.

I think after Be went to the Intel Beige-box, someone hacked a way to do it on them, but after Be dropped the PPC, I lost interest.
-- tomierna, Aug 19 2000


I want this, if for no other reason than the fact that computers lost a lot when they stopped having the blinkenlights. Even if it gives no more information than 'Yes, the computer is still working', I want one...
-- StarChaser, Aug 19 2000


Old Apollo/HP workstations had four LED's that served as a simple bar graph for CPU load. All the mainframes and supercomputers I've seen have had something similar (often one per CPU, leading to a dazzling array on MPP systems).
-- egnor, Aug 19 2000


Boo. Those aren't blinkenlites, they're LCDs. Those aren't any fun...
-- StarChaser, Aug 19 2000


All the things I posted are about LEDs, except for Matrix Orbital, and they make both LCDs and VFDs (vacuum fluorescent displays). If VFDs aren't acceptable blinkenlights, I dunno what is.
-- egnor, Aug 20 2000


Much better to have a light and/or alarm when the CPU or I/O locks up, similar to the system you get in some server boxes that warns you if a system fault occurs (say, one of the fans stops turning).
-- MonTemplar, Aug 20 2000


Best thing about the Connection Machine (OK, so this dates me) is that every one of the 64K processors had its own LED. That's how to do it.
-- rmutt, Aug 25 2000


Yes! Now THEM'S blinkenlites...
-- StarChaser, Aug 25 2000


Actually, I'd sorta like to have a MIPS gauge, to give a clue as to how much of the CPU's time was being spent computing, and how much was spent waiting for cache misses. This would, among other things, give a bit of a clue as to how upgrading CPU speed would or would not improve things (if every other instruction generates a cache miss, a 3.5GHz Pentium VII will work little better than a 400MHz PIII; in some cases the larger cache that will no doubt be present in the P-VII would reduce the number of cache misses, but for some applications that wouldn't help much.)
-- supercat, Aug 25 2000


Baked in an Apple pie with small market share: you can get a Control Panel for Macintosh that puts these two tiny arrows (sort of like the contradiction symbol) in the top left corner to signal hard drive activity. I think it also monitors removable media activity (because Macs don't have LCD's for that).
-- toomuchmike, May 20 2001


You could do this fairly simply using a parallel port on the PC and a little daemon which monitors /proc/whatever-its-called. (There are several of these around which flash the keyboard LEDs.) You could get it to do network activity, too.

The parallel port has (IIRC) about 12 lines which could be used, powerful enough to drive a little LED. Put 'em in a box near the computer, and you have instant blinkenlights. [I just wrote this, and then noticed that the ewal.net page described exactly this. Aaargh!]

Would this interfere with a parallel Zip drive, though?

Another thought: you could get a nice analogue dial by sticking resistors onto some of the lines (to form a crude DAC) and using an analogue voltmeter. Add a back light, and you'd be set ...
-- cp, May 27 2001


Problem with this is it's really hard to tell how much time the CPU is actually computing and how much time it's spending waiting for cache misses, pipeline stalls, etc. Things like the unix system load average only take into account larger-scale interruptions like disk I/O and time-slicing.

Many recent processors have some sort of on-chip performance counters which might record this kind of info, but I don't know for sure (and I don't know if any common OSs give access to these counters).

I've always wanted a usage meter for my network connection: two old-fashioned meters showing transmitted and received bandwidth use. With brass plaques, etc.
-- wiml, May 30 2001


Isn't this like a hardware version of the CPU Usage indicator on the Windows NT Task Manager? If you can stand running NT, you can put this on your system tray.
-- angel, May 30 2001


Most operating systems have a cpu usage meter app. But that's not as much fun as a physical readout.
-- wiml, May 30 2001


I wanted this after seeing it on one of the old Be boxes (dual CPUs, so dual displays.. so sweet). I finally found a co-worker who seemed to have a clue about how to do this without software.. He proposed attaching a piezo speaker between the heatsink and CPU (or a similar place depending upon heat considerations.. maybe mount on heatsink and insulate around it) and the speaker would function as a microphone. A circuit could then theoretically be built to interpret the noise level of the clock as the level activity once it was calibrated.
-- clicket, Sep 24 2001


Hmm, I wouldn't think that the cpu would generate enough noise (electrical or mechanical) for the speaker to pick up. In the case of electrical noise, too, I'm dubious that it would correlate well with the amount of work the cpu is doing.

Maybe you could attach a sensitive, fast-responding temperature gauge to the cpu? Might show something interesting (or maybe not).
-- wiml, Sep 24 2001


To both be considerate to blind computer users and remind myself how old I am getting - (crackly, weak voice cuts in) I remember mainframes with built-in speakers that would let you hear what the processor was doing. You could distinctly identify a tight loop, certain regular operations, or (if you were lucky) where in the loading sequence something was going wrong. I heard of a program that could even play a tune just by being executed (must have suspended itself or done some IO operations between notes and chosen specific loops to produce different notes). So the sound idea is baked clicket and wiml.

Obviously with multi-megahertz (or should I say gigahertz) processors there needs to be some conversion between actual frequency inside the processor and that of the sound emitted. And maybe some change of pitch or timbre depending on what is happening?
-- snagger, Sep 25 2001


"ideally you could have a whole bunch of lights flashing all the time" nice for epileptics eh?
-- dekoi, Sep 26 2001


i just want 2 lights:
1. A "This is a good noise" light
2. A "This is a bad noise" light
forget the power light, generally i know when my PC's turned on y'know
-- dekoi, Sep 26 2001


I used to work in prepress with mac's & the best & simplest way I found to check machines had not frozen was to turn on the seconds on the clock. Intense activity can lock out the clock, but if it didn't click over after 15 ish seconds I was hitting reset
-- darndog, Sep 26 2001


http://casemods.pointofnoreturn.org/cpumeter/ LED meter- works under windows monitors all you need :) Plus a tutorial how to make the led blinkenlights
-- Zero0116, Mar 17 2002


(Put [Zero0116]'s inline link in links area.)
-- phoenix, Mar 18 2002


http://www.atomicmpc.com.au/forums.asp?s=2&c=9&t=2

What do you think of this???
-- goth, Feb 05 2003


The old DEC PDPs used to have a whole series of lights on the front panel showing:

CPU instruction register CPU data address register CPU instruction address

at least. These were 16 bits long separate light for each bit. In 1980 16 bits were quite something.

Below that were toggles to allow you to load in an instruction, location and memory contents into the registers in binary then flick 'run' and watch the pattern. This pattern, and the rattle of the RP05 hard disk head solenoids told you if the system was booting properly or not.
-- timbeau, Jan 14 2004



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