Attention Kprobe/Cdspeed scans unreliable under Win98se

Hi there,

Just to say that Pi/Po scans [made with Kprobe or Nero Cd speed 3.x, doesn’t matter] are unreliable under OS Windows 98, and possibly under Windows Me.
The Pi/Po values of same disc can be considerably lower if other processes are loading the CPU.

On the other hand Win2k / XP are more reliable :wink:

How can you notice it?
The scan are highly dependent on CPU load and hence, the way OS shares the time among processes running.

Under Win98se/Me, if you scan Pi/Po running only Kprobe2 or Nero CDspeed ‘alone’, you will have more reliable values.

Why?

Well, I don’t now exactly but you can test it yourself: just scan [same discs] with and without parallel processes running. The most load to your CPU, the better [lower, but FALSE] Pi/Po values.

It is likely to be related to sampling rate or so. Experts would explain it :wink:

Best regards,

Although I am interested in your observations, I am not an expert. Did the scan patterns look very different also? Would you provide some data, including sampling intervals?

I have a lot of scans, but would need to search on my saved PNG files for this purpose. But I can answer your questions right now…

(a) Pattern (= ‘aspect’, ‘curve profile’): not very different, if CPU is not heavily loaded. Very different if heavily loaded.

(b) Sampling intervals / rate: Ah!, wise / key question :wink: It changes a lot depending upon CPU load, under Win98se… Not the case under Win2k :slight_smile:

Did you get the same speed shape with and without added load?

The same has been known for lower speed cpus (or if you have lots of heavy background tasks) using a high scanning speed.

The drive is just one part of the reporting equation. The drive must be polled at regular intervals for the error data. If that does’t happen, then the sampling because pseudo-random and may not be accurate.

I have seen similar information elsewhere, but never with data shown. Do you have any such results using CD-DVD Speed rather than Kprobe? Kprobe does not show speed curves.

I have also found the results to be unreliable in Win2000 when listening to internet radio or doing anything with WMP.