
By Rob
Wed Mar 09, 2005 10:25 am
Last weekend Ak.Sys freaked out during a short data copy from PC to MPC. It needed a logoff or reboot of the PC to get Ak.Sys working again. But during the next copy session the problem repeated. Ak.sys crashed during the copy process. This repeated on and on, and I tried tens of times, over a period of 1-2 hours.
So I wondered what went wrong, since I had successfully copied about 1.5 GB to the 4k, a couple of weeks ago. But I rember it failed the first time, and worked the second time. Something was on the edge of failing maybe...
First thing I tried was pulling all other USB cables from the PC, so that only the USB cable between PC and 4k was inserted in the PC's USB ports. No luck. Same hangups.
Then I decided to replace the cable between PC and 4k with another one, bypassing a USB hub. This worked! Copying now worked flawlessly for the rest of the day, for many, many hours and I copied tons of to the 4k, in tens of copy sessions. I also noticed that the max speed increased from around 580 k/s to around 625-ish.
So I now suspect the USB hub that is normally placed between PC and 4k. Maybe the hub has bugs (there's software in there!) that pop up when huge amounts of data are transmitted. Maybe the hub introduces a new kind of message during stress (e.g. reporting a failed data package) that Ak.Sys cannot handle. Maybe the hub introduces delays (during stress) that trigger a timeout situation in Ak.Sys. I don't know really.
Whatever the reason, the hub is history!
So I wondered what went wrong, since I had successfully copied about 1.5 GB to the 4k, a couple of weeks ago. But I rember it failed the first time, and worked the second time. Something was on the edge of failing maybe...
First thing I tried was pulling all other USB cables from the PC, so that only the USB cable between PC and 4k was inserted in the PC's USB ports. No luck. Same hangups.
Then I decided to replace the cable between PC and 4k with another one, bypassing a USB hub. This worked! Copying now worked flawlessly for the rest of the day, for many, many hours and I copied tons of to the 4k, in tens of copy sessions. I also noticed that the max speed increased from around 580 k/s to around 625-ish.
So I now suspect the USB hub that is normally placed between PC and 4k. Maybe the hub has bugs (there's software in there!) that pop up when huge amounts of data are transmitted. Maybe the hub introduces a new kind of message during stress (e.g. reporting a failed data package) that Ak.Sys cannot handle. Maybe the hub introduces delays (during stress) that trigger a timeout situation in Ak.Sys. I don't know really.
Whatever the reason, the hub is history!

