For the partition in question, the starting offset is 156,860,678,144 which divides evenly into 128k (131072). So, doesn't look like the issue. Also divides nicely into several further powers of 2 if the block size were smaller. ________________________________________ From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on behalf of Roger Binns [rog...@rogerbinns.com] Sent: Friday, November 30, 2012 2:00 PM To: General Discussion of SQLite Database Subject: Re: [sqlite] Windows (slow) vs. iOS/OSX (fast) Performance
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 30/11/12 13:31, David de Regt wrote: > Only possible agent is MSE, MSE is the best behaved. Norton and similar are especially bad. > ... and process monitor doesn't show it eating IO Sadly that rules out easy fixes :-) > I tried changing block size to the native block size and it only sped > up by ~5%. Although that helps, I was talking about alignment. This can happen at a minor level - eg a small block size could be 4kb but the partition starts at 63kb. That means each filesystem block maps onto parts of two different SSD/HDD blocks. For SSDs there are also major block sizes (erase block) which typically tended to be 128kb. Again a misalignment could cause a lot of extra work to be done. Depending on how Windows got partitioned - the older the partitioning the more likely this is to happen. It won't shouldn't using a current Windows 7/8 on a fresh machine today. Run msinfo32 and then Components > Storage > Disks to find the relevant partition and its starting offset/alignment. (This is unlikely to be your problem, but if present does result in the kind of performance degradation you are seeing.) Roger -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEARECAAYFAlC5LIYACgkQmOOfHg372QQTsgCg1kUbwbwBnJOcenMHnFULGZe5 PqcAn30XBAT6extxig8Md7MI6XEtoHbi =xYNE -----END PGP SIGNATURE----- _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
