wanamino Posted June 8, 2010 Share Posted June 8, 2010 Hi, as you know, manufacturers are moving to a new internal hard drive format, (Western Digital mostly) were sectors are 4096 bytes size, discarding the old one of 512 bytes. As I have understood only systems "legacy" as Win XP and lower are affected ... you know someone about it, which takes effect systems OS X. .. and the hacks? I personally think that the old installations based on MBR will suffer performance penalty, and GID based real macswon't have any problem...but...What about bootloaders? Can i use any new disk with 4096 bytes sector size without care in partition aligment in the bootloader or any other problem? Any real world experience about? Thanks in advance. Link to comment Share on other sites More sharing options...
wanamino Posted June 9, 2010 Author Share Posted June 9, 2010 any help..? Link to comment Share on other sites More sharing options...
srs5694 Posted June 12, 2010 Share Posted June 12, 2010 I wrote an article about this with respect to Linux on IBM developerWorks. You can read that if you like, but keep in mind that it's rather Linux-centric. In theory, the same issues apply to Hackintosh installations, but in practice you're likely to use different partitioning tools. I also don't know how susceptible HFS+ is to the performance problems that Advanced Format disks can provoke. If you use Apple's Disk Utility to partition the disk from the start, you shouldn't have problems, since Disk Utility aligns all partitions to 4096-byte boundaries by default. If you initially set the disk up using a utility in another OS, then it depends on the OS and utility, but in general, all bets are off. If you used the default Windows Vista or Windows 7 utility, you should be OK; but if you used most others, the chances of your having problems are rather high. If you're in doubt, I recommend you check it out with a utility that provides sufficient precision about the location of each partition's first sector (many disk utilities are lacking in this regard). I'm most familiar with Linux tools, so I'll suggest you get the System Rescue CD or PartedMagic (two Linux-based emergency recovery systems), boot it, open a text-mode prompt, and type "fdisk -lu /dev/sda" (for MBR disks) or "gdisk -l /dev/sda" (for GPT disks) to view your disk. (You may need to change the device ID from /dev/sda to /dev/sdb, /dev/sdc, /dev/hda, or something else. Type "ls /dev/[hs]d?" to see your available disk devices.) The results will look something like this (shown for both MBR and GPT disks on one of my Linux systems): # gdisk -l /dev/sda GPT fdisk (gdisk) version 0.6.8 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. Disk /dev/sda: 1953525168 sectors, 931.5 GiB Logical sector size: 512 bytes Disk identifier (GUID): 2E8FE240-FC7A-0294-7068-8EB94CBF4005 Partition table holds up to 128 entries First usable sector is 34, last usable sector is 1953525134 Partitions will be aligned on 8-sector boundaries Total free space is 6 sectors (3.0 KiB) Number Start (sector) End (sector) Size Code Name 1 40 439 200.0 KiB EF02 BIOS boot partition 2 440 410039 200.0 MiB EF00 EFI System 3 410040 819639 200.0 MiB 0700 Linux /boot (unused) 4 819640 1229239 200.0 MiB 0700 Linux /boot (unused) 5 1229240 1953525134 930.9 GiB 8E00 Linux LVM # fdisk -lu /dev/sdb Disk /dev/sdb: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Disk identifier: 0x00022117 Device Boot Start End Blocks Id System /dev/sdb1 * 63 192779 96358+ 83 Linux /dev/sdb2 1012095 625137344 312062625 8e Linux LVM /dev/sdb3 192780 1012094 409657+ 82 Linux swap / Solaris Partition table entries are not in disk order Note the "Start" column in both types of output. If the values are multiples of 8, you're fine. If not, then you'll have problems. In this example, the first disk is properly aligned, but the second one isn't. (The second disk in my example isn't actually an Advanced Format disk, so it doesn't actually have any problems. It was just handy as an example.) You can use the techniques described in the article to which I linked earlier to create new partitions for a Hackintosh install, or use Disk Utility if that's practical. If you've got a disk that's already suboptimally configured, perhaps you can use the utility provided by Western Digital on their Web site to fix the disk. Link to comment Share on other sites More sharing options...
wanamino Posted June 15, 2010 Author Share Posted June 15, 2010 Superb reply, totally speechless. Thank you very much, now i understand it perfectly (almost) Talking about partitions tools i will give a try PartedMagic, but wanna try with WinHex (win32 hdd forensic tool, very cool) Link to comment Share on other sites More sharing options...
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