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Which Is faster to boot from
- Thread starter BKavanagh
- Start date
If the disks are capable of the same UDMA
assuming that the boot files and neccesary files to start windows is optimized in both scenarios it should be the same (from the first sectors on disk).
Else the one with higest UDMA mode is prefered .
//Regards Soaplover
assuming that the boot files and neccesary files to start windows is optimized in both scenarios it should be the same (from the first sectors on disk).
Else the one with higest UDMA mode is prefered .
//Regards Soaplover
The boot sector and partition table will already be buffered in either disk by time the loading routine for the O/S is called, assuming the disks have both spun up and initialized.
UDMA speed will be rather inconsequential for delivery of the first few sectors. You will notice a difference after that dependent on a number of factors (in rough order of impact):
1. The internal transfer rate of the drive. Nothing beyond the first few sectors will be in the disk buffer - the rest of the boot and O/S loader routines will have to be read off the platter. That transfer rate is dependent on the rotational speed of the disk and the density of the data on the outer few cylinders of the platter. If both of your drives are 5400 RPM for example, then the 20GB drive is likely to have a higher number of sectors on the outer physical cylinder. It will be able to read a certain percentage more data for one revolution than the 7GB drive. This all assumes you are booting from the first partition on the drive, and that partition starts at the beginning of the drive.
2. The arrangement of O/S files on the drive. Best case is a completely unfragmented drive where the O/S loader files are physically on the outer cylinders. The 20GB drive suffers a bit if the entire drive is partitioned as one large partition. The FAT is larger and takes up more room on the faster outer cylinders. Files are pushed inward to progressively slower cylinders, and the head(s) must swing out to read that data. If both drives are single-platter, the total effect might only be a few milliseconds, which the 20GB drive probably can make up easily reading the O/S files (because of it's faster internal transfer rate).
3. Size of the on-disk buffer, internal read-ahead settings. Aside from published specs that give the total buffer size, you really don't know how much is useable or how read-ahead is set. Assuming about the same generation of drives and roughly the same buffer size, the overall effect on file reading operations during boot is extremely small.
4. IDE Speed - listed last because the CPU is primarily waiting for the drive to read data off the platter for maybe 99% of the disk-related boot process. The other 1% is spent transferring the data, so that small piece will be quicker if a faster interface is used.
If you're using Windows, there are internal cache settings that change drive behavior and performance, but both disks should be equally affected (although it's possible to intentionally change them per partition).
If the drives are roughly the same vintage, then I expect the 20GB would be marginally faster. This may not hold if the 7GB drive is newer, higher RPM, or of a generally higher quality, or the 20GB drive is fragmented at the file and O/S level vs. the 7GB drive.
UDMA speed will be rather inconsequential for delivery of the first few sectors. You will notice a difference after that dependent on a number of factors (in rough order of impact):
1. The internal transfer rate of the drive. Nothing beyond the first few sectors will be in the disk buffer - the rest of the boot and O/S loader routines will have to be read off the platter. That transfer rate is dependent on the rotational speed of the disk and the density of the data on the outer few cylinders of the platter. If both of your drives are 5400 RPM for example, then the 20GB drive is likely to have a higher number of sectors on the outer physical cylinder. It will be able to read a certain percentage more data for one revolution than the 7GB drive. This all assumes you are booting from the first partition on the drive, and that partition starts at the beginning of the drive.
2. The arrangement of O/S files on the drive. Best case is a completely unfragmented drive where the O/S loader files are physically on the outer cylinders. The 20GB drive suffers a bit if the entire drive is partitioned as one large partition. The FAT is larger and takes up more room on the faster outer cylinders. Files are pushed inward to progressively slower cylinders, and the head(s) must swing out to read that data. If both drives are single-platter, the total effect might only be a few milliseconds, which the 20GB drive probably can make up easily reading the O/S files (because of it's faster internal transfer rate).
3. Size of the on-disk buffer, internal read-ahead settings. Aside from published specs that give the total buffer size, you really don't know how much is useable or how read-ahead is set. Assuming about the same generation of drives and roughly the same buffer size, the overall effect on file reading operations during boot is extremely small.
4. IDE Speed - listed last because the CPU is primarily waiting for the drive to read data off the platter for maybe 99% of the disk-related boot process. The other 1% is spent transferring the data, so that small piece will be quicker if a faster interface is used.
If you're using Windows, there are internal cache settings that change drive behavior and performance, but both disks should be equally affected (although it's possible to intentionally change them per partition).
If the drives are roughly the same vintage, then I expect the 20GB would be marginally faster. This may not hold if the 7GB drive is newer, higher RPM, or of a generally higher quality, or the 20GB drive is fragmented at the file and O/S level vs. the 7GB drive.
As 7 gig HD's havn't been available to buy for a good time now and you can still find the odd new 20gig 4 sale, I would make an assumption here and say the 20 is likely to be a newer model that the 7 and that as speed increases generally with every new model release, the 20, based on the premise that both are slower 5,400rpm spin speed, will be faster by vertue of the slight advancement in technology.
Not withstanding Dreamlands theories.
Martin
Replying helps further our knowledge, without comment leaves us wondering.
Not withstanding Dreamlands theories.
Martin
Replying helps further our knowledge, without comment leaves us wondering.
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