The performance decrease is likely the result of flash performance more than the recycling when full.  The flash erase operation typically is the command requiring the most time to complete.  It would be interesting to determine if filling the cache when using RAM based media results in similar performance degradation.  Attached is .reg file to increase the size of cache disk and restore the internet cache directory to cache disk.

According to Microsoft there is no automatic way to clear the entire cache.  The suspicion is that when the cache was stored in Cache Disk, it was cleared as a matter of course during normal operation (reboots, etc.)  Now that it is in persistent store, it must be cleared manually.  Microsoft has provided two APIs: DeleteUrlCacheEntry and FreeUrlCacheSpaceA both are exported from WININET.DLL

George thanks for the clarification. If i understand correct the following is changed. On  OEM 27 the IE temporary files were stored on Cache Disk by default. so even without the MS mechanisme these temp files were deleted after a warmboot because of the Cache Disk behavior. On OEM 35 IE temporary files are in Program store with a size limit of 5mb. if that limit is reached then MS mechanisme starts to remove some files. Now to the TA complaint he is saying that when the cache in Program store is full the device is slowing down. is there someway to check if the MS mechanisme is working as designed or what the CPU usuage is of this process.

Maybe also good to communicate this change of behavior around temporary internet files on OEM 35 to a wider audience. AFAIK a wide audience is under the impression that default behavior of Cache Disk is taking care of clearing temporary internet files, as it one of our Value adds.

I think that there are really 2 distinct questions stuck in there. 1) What mechanism is used to clear the cache? 2) Why was the cache parameters changed in BSP35? I have some answers to #1 and I'm waiting for answers to #2. 1) From Microsoft, the CacheLimit value describes the maximum size to be used to store IE data.  When the limit is reached and a new entry is required, IE will use a number of parameters to decide which of the existing entries need to be removed.  IE will look at size, hit rate, age and other factors to decide which existing entries to be removed.  At no time will the entire cache be erased automatically.  A user needs to perform that function manually.

BSP 35 was the first BSP to include Internet Explorer 6 which included a recommended IE cache size of 5MB becuase of support for richer page content, AJAX, JScript v5.7, etc.  As noted above, prior to BSP 35 Cache Disk was used to store temporary internet files and the physical size of the cache disk became the control size (default 4MB).  Because the default size of the of the cache disk is smaller than the recommended 5MB limit it is not used by default for IE Cache.  Furthermore since the program store is now used (\Windows\Profiles\gues\Temporary Internet Files) for the files a legitimate cache size value had to be utilized.

bump , any answer is appreciated around this topic