Palit 9800 pro 128bit has been installed for several days. After some time, I noticed that the power supply was clearly louder than usual. I figured the reason was the increased use of the 5V line over the ti4200 8x which I used before. I also got interested in the data on energy consumption on individual lines of the power supply provided in this thread
PSU for Athlon XP 3200+, Radeon 9800 XT?
I have a multimeter. I have never measured the amperage, and the topic of sA energy consumption is perfect for learning. In order not to extend the topic, I will only describe the final successful measurement attempts. Previously, I had a problem with computer reboots due to too small contact surface between the wires and the multimeter sockets.
The first idea was to measure the current separately on each of the four 5V lines in a 20pin plug. Effect - each line (during the measurement) consumed about 0.4A. Assuming that all 5V cables are connected in the power supply, it would mean that the overclocked platform uses 4 * 5V * 0.4 = 8W, which of course is not possible. Another thought - maybe this board used 12V line. (20pin plug has only one 12V wire) Measurement read 0.09A regardless of load, so no. Bad contact surfaces created additional resistance through which more current flowed through the remaining lines (i think so). Please do not call the fire department - I have finished my measurements and no building has burnt down.
Since all 5V wires in the molex plug come from one point in the power supply (I know it is so, I checked), they need to be connected, run through a multimeter and then lead to the 20pin plug. Theoretically, I could only connect one wire from the meter to the mainboard (the board started),or only one wire from PSU, but it would theoretically cause four times more current on the tracks, which could end up damaging the board. And the problem with bad contact of individual wires. Finally, for successful measurements it looked like this.
Here are the measurement results. It turned out that the multimeter is not suitable for what I do because ... I exceeded its measurement range.
Current on the 12V line in 20pin (unchanging, regardless of the load) - 0,09A
Def: AXP T-bred 2700+ 166x13 1,65V; ram 166 2:2:2:9 2,7V
OC: 187x13 1,8V; ram 187 2:3:2:9 2,7V
Q3A - Def: 12,6A ; OC: 19,3A ; Delta: 6,7A
SuperPI - Def: 12,4A ; OC: 18,5A ; Delta: 6,1
Doom3 - Def: 13,4A ; OC: out of scale
Prime95 - Def: 15,1A ; OC: out of scale
At least the energy measurements for the graphics card were easy. Everything is clear here. Desktop - 3.6A, games - 4.2A. 12V desktop - 0.75A
Assuming, with a slight margin of safety, that the difference between Def and OC in Prime is 7A, after OC - the platform takes 22.1A from the 5V line. By adding 4.2A from the GPU, we get a current of 26.3A, which means that for several days I have been exceeding the maximum current for my power supply 😀 Ofc assumed delta could be lower but discussed results are made for 1.8V, and I used 1.825V on a daily basis ... 😀