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How common is 'advanced format' now?

P

pmv

Lifer
As I'm still using XP I'm wary of 'advanced format' drives (I know there are ways round it, but from what I've seen even when drives are realligned it still impacts performance). The only articles I've seen about it refer only to Western Digital drives but seem to suggest it will be adopted by other manufacturers. Has this happened now or not? Is it still a WD-only issue?

(It does seem I'm not going to be able to hang on with XP for a lot longer, but I just can't face setting everything up again with a new OS)
 
I'm only aware of WDC "advanced format" disks. But Seagate and others have announced 3 TB disks for late 2010 and they'll certainly need the enhanced error correction ability of this formatting technology for those large disks.
 
Seagate blogs has more info about it. From what I read on their site, at 2011 all new models from several manufacturers ought to be advanced format. However, I wouldn't worry about it... just don't buy one if you're on XP.
 
RebateMonger said:
I'm only aware of WDC "advanced format" disks. But Seagate and others have announced 3 TB disks for late 2010 and they'll certainly need the enhanced error correction ability of this formatting technology for those large disks.
Click to expand...

actually, it is impossible to go above 2TB drives with the current implementation of 512b sectors. So you would need 4kb sectors for those drives (or create a new implementation of 512B sectors... but why bother?).

I don't like the way WD has implemented it, they emulate 512b sectors (cannot be turned off) and have a jumper that ofsets the addresses to account for XP being obsolete POS. This means problem for anyone who uses it in a modern OS... when you make top of the line hardware you shouldn't cripple in order to be compatible with obsolete OSes.

Also... move away from XP already... If you don't want windows 7 x64 then at least get ubuntu with wine. (not that XP doesn't have its place... i dual boot win7x64 and winXP so that I could run some ancient games which are not compatible with modern OS...)
 
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hanspeter said:
Impossible? Even on modern OSes? Says who?
Click to expand...

I am told there is a limit of addressing space, which limits the current implementation to 2TB unless you increase the size of each address or increase the size of each sector (or both).
But I cannot recall the source on that one, and I just reviewed the anandtech article about advanced format and it has not mentioned that. So maybe it is wrong.

Anyone knows the how many bit the addresses are? I just did some math and found out that @512B sectors, 2TB would be a 21bit long address which is an odd number.
 
This article applied to NT, but I'm guessing that the math is still the same:

http://support.microsoft.com/kb/q114841/

"NTFS uses 64-bit fields for all sizes, permitting its data structures to handle volumes up to 2^64 bytes (16 exabytes or 18,446,744,073,709,551,616 bytes).

This value is the theoretical limit for the NTFS file system. Practical limits having to do with the maximum allowable partition size described above limit the size of an NTFS partition to approximately 2 terabytes. Because the 32-bit fields of the partition table refer to the number of sectors in the partition, disks with larger sector sizes translate into larger permissible partition sizes. Currently Windows NT supports sector sizes up to 4 Kilobytes. With 4KB sectors, Windows NT can support a 16 terabyte partition. As new hardware or software schemes become available, NTFS will be able to handle substantially larger volume sizes."

If I'm reading this correctly, then, yeah, you'd need 4 KB native sectors to get to 16 TB partition size, and 512 Byte sectors will only get you to 2 TB. Note that the current WD "Advanced Format" disks all use emulated 512 Byte sectors, as far as I know.

This article:
http://mkp.net/pubs/lsf09-io-topology.pdf
says that, for now, Enterprise disks will come with native 4 KB sector sizes, while Desktop disks will come with the emulated 512 Byte sectors. The 3 TB disk that Seagate has "announced" will be an Enterprise disk.
 
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hanspeter said:
GPT is an option in Windows today.
Click to expand...
But GPT won't get around any limitations imposed by NTFS. NTFS would normally be used (in Windows, at least) to format any partition, whether it's a GPT partition or an MBR partition.

I could be wrong, but what I'm getting from this is:

- NTFS uses 64-bit addresses (which is what taltamir asked)
- NTFS needs 4 KB sectors to go above a 2 TB partition
- MBR partitions can only handle a 2 TB disk, so GPT partitions will be necessary to go larger.
- I have no experience with partitions larger than 2 TB, but if I had to guess, when a RAID card presents a virtual disk larger than 2 TB, it's probably emulating a 2 KB or 4 KB sector size so that NTFS can format it (assuming you're using GPT partitioning to create "large" partitions).
 
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You can format volumes way greater than 2TB with NTFS. The kb you quoted is about how you partition the drive by using the MBR scheme.
 
hanspeter said:
You can format volumes way greater than 2TB with NTFS.
Click to expand...
Using what Sector and Cluster sizes?

It seems that NTFS will try to use "standard" 4 KB clusters, which would need sectors larger than 512 Bytes to go above 2 TB partitions.
 
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RebateMonger said:
This article applied to NT, but I'm guessing that the math is still the same:

http://support.microsoft.com/kb/q114841/

"NTFS uses 64-bit fields for all sizes, permitting its data structures to handle volumes up to 2^64 bytes (16 exabytes or 18,446,744,073,709,551,616 bytes).

This value is the theoretical limit for the NTFS file system. Practical limits having to do with the maximum allowable partition size described above limit the size of an NTFS partition to approximately 2 terabytes. Because the 32-bit fields of the partition table refer to the number of sectors in the partition, disks with larger sector sizes translate into larger permissible partition sizes. Currently Windows NT supports sector sizes up to 4 Kilobytes. With 4KB sectors, Windows NT can support a 16 terabyte partition. As new hardware or software schemes become available, NTFS will be able to handle substantially larger volume sizes."

If I'm reading this correctly, then, yeah, you'd need 4 KB native sectors to get to 16 TB partition size, and 512 Byte sectors will only get you to 2 TB. Note that the current WD "Advanced Format" disks all use emulated 512 Byte sectors, as far as I know.

This article:
http://mkp.net/pubs/lsf09-io-topology.pdf
says that, for now, Enterprise disks will come with native 4 KB sector sizes, while Desktop disks will come with the emulated 512 Byte sectors. The 3 TB disk that Seagate has "announced" will be an Enterprise disk.
Click to expand...

Thank you, this is what I was referring to. I was told this but did not have a qualified source or even knowledge of the exact reason why.
It does to explain why and to specify that indeed 2TB is the hard limit without making changes.
 
taltamir said:
Thank you, this is what I was referring to. I was told this but did not have a qualified source or even knowledge of the exact reason why.
It does to explain why and to specify that indeed 2TB is the hard limit without making changes.
Click to expand...
Well, I'm not sure that I have anywhere near a complete understanding of the interactions of MBR/GPT and NTFS. But I'm no longer convinced that you need 4 KB sectors to format a 2 TB+ partition in NTFS.

MBR is obviously a problem, since it can't handle a disk larger than 2 TB. But it seems you could go to GPT partitioning and use 8 KB clusters and use 512 byte sectors and format a 4 TB partition. NTFS file compression will stop working because of the 8 KB clusters and storage will not be as "space-efficient", but I'm not seeing why NTFS couldn't be used to format a 2 TB+ partition with 512-Byte-sector GPT partition.
 
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I am not sure why you are questioning NTFS. You don't need to make any changes to it. It can handle anything today with normal size clusters.
 
I'm confused by this discussion. Even if you are limited to 2Tb _partitions_ as the extract quoted above states, why can't you have larger physical disks, just with multiple partitions?
 
pmv said:
I'm confused by this discussion. Even if you are limited to 2Tb _partitions_ as the extract quoted above states, why can't you have larger physical disks, just with multiple partitions?
Click to expand...

you could but it would be really clunky... and hard to deal with for many people.
 
The MBR partitioning scheme: you are using 32bit absolute pointers. So you cannot go beyond 2TB total - nomatter to numbers of partitions you create.
 
pmv said:
I'm confused by this discussion. Even if you are limited to 2Tb _partitions_ as the extract quoted above states, why can't you have larger physical disks, just with multiple partitions?
Click to expand...
As hanspeter notes, if you create MBR partitions on a disk, the total of all the partitions can't be greater than 2 TB. The rest of the disk will go to waste.

If you want to use all of a 2 TB+ disk in Windows, you have to create GPT partitions on it. Once you've got one or more GPT partitions, you can format it with NTFS.
 
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taltamir said:
you could but it would be really clunky... and hard to deal with for many people.
Click to expand...
No you can't. The MBR partitioning scheme allows for 32-bit addressing, 32-bit of 512-byte sectors means 2TiB limit. Beyond that, there is nothing to access using MBR. So you cannot create any partitions beyond the 2TiB barrier. Creating multiple partitions to exceed the 2TiB barrier will therefore not work.

You either should not use partitions at all, which is only possible under non-Windows OS, or you have to use GPT partitions. The problem here is that you need BIOS support which can boot from GPT partitions and Windows also needs to support GPT boot; not sure which versions support it but i do know some only allow storage but not booting from GPT disks.

So the 2TiB barrier is not that easy to circumvent. One possibility is to use 4096 sectors, but to my knowledge, for that to work you need a drive that exposes 4096 byte sectors not like the WD EARS drives which still say they have 512 byte sectors. With 4K sectors you would have 8 times the storage capacity; or 16TiB.
 
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So what's the situation for the near future? As we are clearly about to go over the 2Tib boundary?

Wiki on GUID partition seems to say that no 32-bit OS can really handle GPT (not even 7), so presumably that means a 64-bit OS is essential for larger drives just as it is for more than 4Gb RAM?

Or is the point that with 4k sectors you can continue to use MBR, and hence 32bit OSs will still work? Is there an intention to drop MBR or not? If not, why was GPT introduced at all, but if so then presumably 32-bit OSs are dead?

Does the WD 'fudge' allow XP to use >2Tib drives or not? Is this fudge solution itself something that will become obsolete fairly rapidly?

I'm pretty confused!
 
32-bit OS should be able to use GPT; i can't think of any reason it wouldn't. It's not like 32-bit OS cannot handle numbers bigger than 32 bits; they would use two 'words' and get 64-bit.

It's the MBR partition scheme; which is limited to 32 bits of addressing. If you would use a higher number the BIOS could not boot it any longer. Thus, MBR is limited to 32-bit or 2TiB with 'normal sectors'.

The point of 4K sectors is to make drives more reliable, and use the real estate of the platter surface more efficiently. The point of GPT partitions is to make partitions beyond 2 terabyte possible. I'm not familiar with the 'fudge solution' you talked about.
 
hanspeter said:
You can format volumes way greater than 2TB with NTFS. The kb you quoted is about how you partition the drive by using the MBR scheme.
Click to expand...

Gah... tell me your not thinking in a raid scenario.. :hmm:

Because each disk is still under the 2TB quotta.
 
sub.mesa said:
32-bit OS should be able to use GPT; i can't think of any reason it wouldn't. It's not like 32-bit OS cannot handle numbers bigger than 32 bits; they would use two 'words' and get 64-bit.

It's the MBR partition scheme; which is limited to 32 bits of addressing. If you would use a higher number the BIOS could not boot it any longer. Thus, MBR is limited to 32-bit or 2TiB with 'normal sectors'.

The point of 4K sectors is to make drives more reliable, and use the real estate of the platter surface more efficiently. The point of GPT partitions is to make partitions beyond 2 terabyte possible. I'm not familiar with the 'fudge solution' you talked about.
Click to expand...


Well I'm just going on how Wiki explains that 32-bit OSs can't boot from a GPT partition.

The 'fudge' I refer to is the business of emulating 512b sectors.

Probably I don't understand this well enough to know what questions to ask.

I'm just wondering whether, ignoring my use of a rapidly out-dated OS, if there's some sort of technological road-bump approaching...or not.
 
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pmv said:
Well I'm just going on how Wiki explains that 32-bit OSs can't boot from a GPT partition.
Click to expand...
This is a Windows-limitation, not a limitation of 32-bit processors.

http://en.wikipedia.org/wiki/GUID_Partition_Table#OS_support_of_GPT

As you can see, virtually all other 32-bit OS support booting from GPT.

So if you're a Windows power-user, perhaps you should use an advanced ZFS NAS as storage, and use only small SSDs of HDDs in the Windows workstation. That would circumvent the Windows limitations, and give you much more flexible and reliable storage setup.
 
aigomorla said:
Gah... tell me your not thinking in a raid scenario.. :hmm:

Because each disk is still under the 2TB quotta.
Click to expand...

I am not. Each disk is not limited to 2TB.

There was a time when each disk was limited to 2TB in a dynamic disk setup in Windows, but that has also changed.
 
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