Re: [Freedos-user] UIDE Performance -- Small Caches DO Work O.K.!
Welcome back! Sent from my iPhone On 23/08/2011, at 23:50, Jack gykazequ...@earthlink.net wrote: For years, I have told people to use as much cache as possible with UIDE, to handle today's large files and still leave space in the cache for DOS directories. Today, Tuesday 23-Aug-2011, I ran experiments using a driver equal to UIDE-S, with a new 10-MB cache size of 1280 8K-byte data blocks. I never liked the 5-MB cache that some users MUST have (only 640 blocks, not enough data!) so I chose to try a 10-MB tiny cache. I ran my usual test of copying a 635-MB video drivers CD to disk. With my regular 500-MB UIDE cache, this test takes around 124 seconds, plus-or-minus about 2. With only the 10-MB cache, the test took 128 seconds, merely 4 seconds more! I checked 25, 50, and 100-MB caches as well, and none suffered in speed from being small-sized! Each performed as well, maybe a hair better in some cases, as the 10-MB cache! So, it seems I may have been All wet! (misinformed) re: UIDE's cache performance v.s. cache size. Users may want to check this on their systems, maybe across a variety of applications. And I expect there are a few large file systems which do need larger caches. But, it now seems that casual users of DOS and UIDE need NOT worry re: using only a 25/50/100-MB cache -- They do seem to perform a LOT better than I expected! Jack R. Ellis -- EMC VNX: the world's simplest storage, starting under $10K The only unified storage solution that offers unified management Up to 160% more powerful than alternatives and 25% more efficient. Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user -- EMC VNX: the world's simplest storage, starting under $10K The only unified storage solution that offers unified management Up to 160% more powerful than alternatives and 25% more efficient. Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] UIDE Performance -- Small Caches DO Work O.K.!
Hi, I cannot resist... in the following read my comments on caching and buffering. Even Windows XP (did not try nore recent versions yet) suffers from bad buffering when copying files from and to the same harddrive. It takes 10x to 100x time compared to copying from one drive to another one. I installed SuperCopier 2.2 beta which catches Explorer copy actions and does them itself. Well, now you are able to define huge buffers... but it does not help much, because its a question of filling and flushing the buffer, as XCOPY did. !!! beware, supercopy has got a bug when using buffers larger than 64k, causing it to abort the operation on files larger than 4 gig. !!! Caching does not help much with operations like this. Ok, caching FAT and directories... When working with large files, you always have to code buffering on your own. For example, I compiled mplex (mpeg muxer) myself using cygwin. Works correctly but uses the wrong file mode. Result is my RAM gets filled with cached data from the target file. Everything else gets paged out. The system breaks down to almost unusable until the process is finished. Then it takes decades to swap in the other programs again... What I want to say is, you can have Terabytes of RAM, it won't help in a case like this when the file operation is about as large as your RAM. If there was an upper limit for the amount of cache used for a single file, there would be no problem at all. So small caches sometimes perform even better! So guys go tell M$ how to write an operating system! JPT -- EMC VNX: the world's simplest storage, starting under $10K The only unified storage solution that offers unified management Up to 160% more powerful than alternatives and 25% more efficient. Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
[Freedos-user] UIDE Performance -- Small Caches DO Work O.K.!
For years, I have told people to use as much cache as possible with UIDE, to handle today's large files and still leave space in the cache for DOS directories. Today, Tuesday 23-Aug-2011, I ran experiments using a driver equal to UIDE-S, with a new 10-MB cache size of 1280 8K-byte data blocks. I never liked the 5-MB cache that some users MUST have (only 640 blocks, not enough data!) so I chose to try a 10-MB tiny cache. I ran my usual test of copying a 635-MB video drivers CD to disk. With my regular 500-MB UIDE cache, this test takes around 124 seconds, plus-or-minus about 2. With only the 10-MB cache, the test took 128 seconds, merely 4 seconds more! I checked 25, 50, and 100-MB caches as well, and none suffered in speed from being small-sized! Each performed as well, maybe a hair better in some cases, as the 10-MB cache! So, it seems I may have been All wet! (misinformed) re: UIDE's cache performance v.s. cache size. Users may want to check this on their systems, maybe across a variety of applications. And I expect there are a few large file systems which do need larger caches. But, it now seems that casual users of DOS and UIDE need NOT worry re: using only a 25/50/100-MB cache -- They do seem to perform a LOT better than I expected! Jack R. Ellis -- EMC VNX: the world's simplest storage, starting under $10K The only unified storage solution that offers unified management Up to 160% more powerful than alternatives and 25% more efficient. Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
