I did not find a way to modify/fix my previous posts,I found,that U r using other formatting tags here( [] instead of <> ),but now it is late,I c no way to fix the tags in my previous post & now the most relevant part-the 1st confirmed backwards compatible new hard drive is very poorly visible with wrong Bold tag,thus I adding it here again in Bold,I wished to have here the PNs of confirmed 512e/n hard drives highlighted to make them easy to find in the rest of text,thus sorry for repeating,but I cannot fix the tags.
[font color=green]WD20SPZX:
CONFIRMED BACKWARDS COMPATIBLE.
2TB WD Blue HDD is still being made as 512e.
I already successfully installed 6 installs of Legacy OSs to 3pcs of WD20SPZX successfully formatted as MBR.
The manufacturer confirmed,the parameter is not about to change.[/]

(...) we know,Advanced Format may be 512e,but it also may be 4Kn (...)

Do you have any references that say or imply this, because this would contradict the currently publicized official documentation [1].

Do you have any examples of drive models with an AF logo that do not support 512e emulation ?

EDIT: Some drives can support either 512e mode or 4Kn mode operation [2].

[1]
https://idema.org/initiatives/advanced-format … -logo-overview/

[2]
https://www.seagate.com/files/www-content/pro … 99-1-1701us.pdf

I have read an article somewhen in 2019,when I was about to buy my 1st AF drive(1 of these WD20SPZX,I am using since then),sorry,I do not remember the precise source,I have read then,but there it was explained,that Advanced Format is everything except 512n,thus AF always has 4KB physical sectors & is distinguished by another parameter to 4Kn with no 512B emulation & 512e with 512B sectors emulation allowing Legacy OSs to c it as if it was 512n,then there was several paragraphs describing the RMW emulation method,I am sure,it was in more articles,but it is 6 years ago,so I remember the content,not the names of the websites & then also the data sheets did contained the sector format,it was usually 1 line bellow "AF" or "Advanced Format", there was "512e" or "4Kn", so I did not needed to contact the helpdesk to ensure,I will not end up with a 4Kn drive,I was then sure,I am buying 512e drive,but about half year ago I noticed,manufacturers removed that line 512e/4Kn from the data sheets.
If there is a new regulation or interpretation of the meaning of "AF",I did not encoutered with it yet,formerly Advanced Format had a meaning of being a non-512n drive,so any drive with other than 512B physical sectors,regardless the presence of the emulation in its controller.
If the definition of the term Advanced Format did changed over those years,thank U for the update.
But still some manufacturers may use the older definition,as they r using another definition of MB/GB/TB units,they also may use various definitions of AF term,if there is more definitions,or it is being redefined by the time,as U imply(or U also may imply,that I am now in another universe,than I was 5 years ago,& as random interactions between neighboring parallel universes causing random exchange of its inhabitants is a valid cosmological theory,it also must be considered),some manufacturers may mean something else by AF than others,thus I still feel a meaning of having a list of confirmed drives sure supporting 512B sectors emulation.
Consensus of other users &/or admins will have the final word or click.
Of course,if it would be proved,that only U r right & there is now only 1 definition of AF & all manufacturers do respect it & thus all drives marked AF r absolutely sure 512e & no risk,they may be 4Kn without emulation,then it would be the best result for all users,builders,restorers,upgraders...,because it will finally solve all worries for all,which is the meaning of this thread,so if the final word is:"Do not worry,none of the AF-marked drive is 4Kn,none lacks the 512B emulation,thus U can buy any drive up to 2TB & install Windows XP on it.",every1 including me will be incredibly happy...if that is really true...
I hope,we can settle on common interest of doing really the maximum for avoiding 4Kn drives,be it by list of confirmed compatible drives or by proving Your opinion,that there is absolutely no risk,an AF drive may be 4Kn.

& I must add(& really I do not c an Edit button,maybe it only appears since some rank above):U did a point about the logo,but when U select a drive in an eshop,there is often a mark,that the image may not match the look of actual product & I mostly find grid-style data sheets with none of the logo,U pointed & there is only a text line "AF" or "Advanced Format", so yes,in a real shop,I probably can ensure myself by the logo on the drive itself,if visible,but in the eshop it is never so clear.
& I also remember 512e logos,but most relevant is,this make U sure,when there is a visible logo,when U have a text specifications without logo only,U cannot be so sure,a text line "AF" /"Advanced Format" always means 512e & never 4Kn.

I can't speak for IDEMA or drive manufacturers, but the Advanced Format logo does not seem to have changed in appearance or meaning, at least officially, since 2013 at least [1].

I agree that drive manufacturers could stand to be clearer in their spec/data sheets.

[1]
https://web.archive.org/web/20131019123607/ht … g/?page_id=2900

I would like to see an example of a drive that doesn't work.

All my 2TB and 3TB drives so far support 512 sector size, am sure that could come to an end soon.
My only other comment is that I hate laptop drives for full PC's, so the WD20SPZX is not something I be looking for.

Horun wrote on 2025-02-23, 05:10:

All my 2TB and 3TB drives so far support 512 sector size, am sure that could come to an end soon.
My only other comment is that I hate laptop drives for full PC's, so the WD20SPZX is not something I be looking for.

I agree.

Especially since nearly all laptop drives (2.5") are SMR now and have been for a while.

darry wrote on 2025-02-23, 02:16:

I agree that drive manufacturers could stand to be clearer in their spec/data sheets.

This is the main point,manufacturers neglects this parameter for every drives except super-expensive Enterprise-drives & it could be irrelevant for some time,but with imminent danger of 4Kn drives r about taking over the market,from now on more & more caution will be needed to avoid them & to focus on remaining 512e drives.
This should be for that extended caution to save some1's nerves in advance...

cyclone3d wrote on 2025-02-23, 03:12:

I would like to see an example of a drive that doesn't work.

Yes,I would like also confirmed 4Kn-non-backwards compatible drives to add to the list as items to avoid.

Horun wrote on 2025-02-23, 05:10:

All my 2TB and 3TB drives so far support 512 sector size, am sure that could come to an end soon.
My only other comment is that I hate laptop drives for full PC's, so the WD20SPZX is not something I be looking for.

The physical sector size of drives over 2TB r irrelevant,as drives larger than 2TB cannot be formatted as MBR(unless U will accept wasting all the space beyond 2TB),thus Windows XP nor older will not c it even as data drive & for 32bit Windows 6/7/8 it cannot be system drive & can only be a data drive,so the limitations r same as for any other GPT drive,cannot install any 32bit OS & cannot even access from Windows 5.1 nor older,for this U need MBR & for MBR U need 512B sectors & drives up to 2TB,because these r limits of MBR.Thus only drives up to 2TB have to be analyzed for backwards compatibility,which basically is the possibility to make it MBR,thus visible & usable for Legacy OSs,so for Legacy purposes U need 512e/n drives up to 2TB.

& yes,that is my concern,if the 512B sector emulation will be discontinued by all manufacturers except Enterprise drives,get any 32bit Windows alive on real HW will become the most expensive hobby & if it will be discontinued also for Enterprise drives,that will be to final end of 32bit era.
Interesting paradox is,if SD cards or flash drives(USB) will remain 512n/e,then 32bit era will be killed even sooner than 16bit era,as 16bit OS setups as DOS 6.22+Win.3.x can happily survive on SD card or USB flash drive,a Win32 will destroy such a drive very soon by consuming all E/P cycles very quickly,so we need HDDs for Win32 & if 512B emulation will be dropped for internal hard drives,we will still be able to have DOS+Win16 on SD card,but no way for installing a Win32.Those,who loves VMs,can sleep well,but for those loving running Legacy OSs natively the end of 512B sectors emulation is a nightmare,on the other hand,maybe we will run out of all Legacy & CSM supported MoBos sooner than we will run out of last 512e drives after they will be discontinued & true is,discontinuing of CSM support on new MoBos is greater concern,as without 512e/n HDDs we will lose the possibility to run natively 32bit OSs,while we will still be able to run 16bit OSs from SD cards,but with no MoBos with CSM we will lose both,but still Win16 & DOS may survive longer than Win32,because most of MoBos capable of running Win32 r RoHS & BGA & will fall apart much sooner,than old good MoBos with Pb,so when all P3/P4/C2D MoBos will be dead,P1 & older MoBos may still be functional,so even with all 512e/n hard drives dead @ a time,U will still be able to run DOS+Win16 via XT-IDE/IDE-CF/SD,so when all Win32 will be imprisoned in virtual machines,DOS+Win16 will still run natively.
For example I have a stuff o P4 MoBos as spare parts,also I have a huge stuff of spare HDDs(mostly IDE) & quite fewer older MoBos & for all the time,I am collecting old HW(25 years),2 of my HDDs died(2 oldest IDE),compared to MoBos quite good,because for the same time 8 P4 & newer MoBos died,2 P3 MoBos died,1 P2 MoBo died,1 P1 MoBo died,& none of my 486/386/286,nor XT died.
Moreover some guy from New Zealand is manufacturing NEW XT MoBos,the same guy,who invented the XT-IDE,so everything,which can run on XT is saved from ending up in oblivion,thus the result is,Win32 platform is now more endangered than DOS...
Thus when U pointed to the same danger,as I feel-the EoL of 512B sectors emulation, probably we shall stuff as much 512e/n drives as possible & those more ritch should staff even more drives,then they need & when manufacturers discontinues 512B sectors emulation,those,who saved more drives,than they need,may sell it to others,who r restoring Legacy systems.
& y I 1st confirmed these laptoP drives?
Because some goes into laptops & some into compact desktops,yes,to a regular desktop I put 3.5" HDD,but I also collect laptops & compact desktops.To some compact desktops 3.5" drive do not fit at all,in other cases there r no space left around the 3.5" drive for air flow,causing insufficient cooling,which is a great HDD-killer,or the construction of the case is totally absurd,like the HDD caddy touching the PSU or even the CPU cooler,so if I used that original stupid construction,HDD would be fried,thus I mount the disk elsewhere in the case,where the thermal conditions r better for the longer survival of the HDD as priority,which U confirmed by confirming manufacturers' plans to move to 4Kn only,so I will not fry a 3.5" 512e HDD in compact desktop in a caddy directly touching the CPU cooler with 2x3GHz C2D touching that cooler from other side,when I have an option to mount the 2.5" 512e HDD elsewhere,with good passive cooling to the case far from processor+good airflow,to which it is on its beginning,so the air sucked from outside not heated by any other component,cold metal on 1 side,cold air passing by other 2 sides-this is the reason,y I put WD20SPZX into a desktop,because it is a tiny compact desktop with critical flaws in case construction,which I compensated for maximizing the longevity of the system-it is meant to the living room,to be connected to TV,because it has nice front panel design to reside near the TV & it will be filled with my favorite sci-fi movies & series,most of them also retro,the oldest I have from 1950 & 1963(yes,I have even something older than Star Trek TOS-The Cage...with Leonard Nimoy & William Shatner 6 years be4 they became Spock & Kirk...U may guess,what it is...),I plan to entertain my visitors by the best sci-fi...in addition to DOS games,including a TrekFest Free for best friends & this piece of Legacy HW loox best for this particular purpose,sadly the good design is counterweight by stupid internal case design,thus I must mod the layout of essential parts.The hard drive is selected regarding the conditions of the surrounding HW & case layout.
When I will buy a 3.5" HDD for a standard desktop or rather tower,I will notify about the disk model & compatibility,but for now all the standard desktops & towers,I was (re)building/restoring,was much older machines,to which I put IDE drives,which r all 512n.& from newer machines I yet constructed rather obscure form factors,but I will build a backup server & that will have new 3.5" HDDs & Windows Server 2008 Enterprise 32bit,the machine is from this era & designed for this OS & this OS will be the best for it,as it will have 8GB RAM & this is the only 32bit OS able to handle 8GB RAM in my collection & has also high historical value,as it is the last 32bit Windows Server OS,I saved that server from scrapping,but with most HW missing,most complicated was to replace the CPU cooler,as it is a BTX & sadly I did not had replacement Xeon,so it has non-original processor now,it will be used for intranet backup of other PCs & here I will try a new 3.5" HDD,because here it will have sense.
& about SMR:
Is it only weaker in performance,or is it also unreliable?
Because performance is irrelevant,the host is SATA 2,so the drive will work @ half of the transfer speed or less & I archive movies & series in SD or LD,mostly DivX,not in HD/FullHD/4K,so I do not need turbo read speeds for playing 350MB DivX episodes or 700MB DivX movies,pretty much of my archive r so old,they was even filmed in SD.Do U remember the analog TV resolution...this will be the load for this drive...
...All old Good Things...

Sabina_16bit. wrote on 2025-02-23, 21:51:

Horun wrote on 2025-02-23, 05:10:

All my 2TB and 3TB drives so far support 512 sector size, am sure that could come to an end soon.

The physical sector size of drives over 2TB r irrelevant,as drives larger than 2TB cannot be formatted as MBR(unless U will accept wasting all the space beyond 2TB),thus Windows XP nor older will not c it even as data drive & for 32bit Windows 6/7/8 it cannot be system drive & can only be a data drive,so the limitations r same as for any other GPT drive,cannot install any 32bit OS & cannot even access from Windows 5.1 nor older,for this U need MBR & for MBR U need 512B sectors & drives up to 2TB,because these r limits of MBR.Thus only drives up to 2TB have to be analyzed for backwards compatibility,which basically is the possibility to make it MBR,thus visible & usable for Legacy OSs,so for Legacy purposes U need 512e/n drives up to 2TB.

Are you sure about not using MBR on all <2TB HD's ? Will check my 3TB on the one XP box, it has a >32GB fat32 512 primary with rest split into a few NTFS parts. Never checked to see if that first part was bootable.
If it is will post it's make and model. Need to dig it out this week.

You can put an MBR partition table on any 512b sector disk, it just limits the partitions to being within the first 2TB. But typically what is done is one of the MBR partitions points to a GPT that has all the "proper" partitions.

I could be wrong, but I think that modern SATA HDDs behave similar to SSDs.
That means that they support both the 4k and 512 Bytes "protocol" for communications to the computer (to SATA controller/OS).

Internally, the HDDs and SSDs likely do use 4KB blocks.
So it makes sense to align NTFS to match this.

Since Windows XP Setup starts at sector 63, the alignment will be off by default.
Using GParted to fix it or using Windows 7 Setup to create a fresh NTFS partition might be recommended (uses 2MB boundary).

In the past, some new HDDs (Seagate?) had a jumper to fix (hack) the sector 63 misalignment by adding one sector if jumper was set.

Edit: Some HDDs also have a maintenance software that allows capping the storage capacity.
That might be useful for Windows XP, not sure.

A drive has to be one or the other, it can't support both sector sizes.

I bought 6 brand new drives in last ~2 years.
1) Exos X20 20TB HDD (made 2023),
2) Samsung 870 EVO SATA (made 2023),
3) WD SN850X 2TB NVMe (made 2023),
4) Micron 2TB MX500 SATA (made 2024),
5) Samsung 990 Pro 2TB NVMe (made 2024).
6) WD DC HC550 18TB HDD => this one is still on it's way to me (should be here on Wednesday though 😁)

Important part is this :
ALL drives listed were preformatted with 512e mode, NONE came in 4Kn mode by default (even if it was supported).
Example : Seagate Exos X20 20TB drive is 4Kn drive, but I had to manually forced the change to 4Kn using SeaChest utility. I can reformat drive to use sector size 4Kn or 512e [not sure about other ones ones], but to switch between them a full format of drive is required.

Here's how 512n drive (old NVMe SSD), compares to Exos X20 in 4Kn mode :

4Kn drives in 512e mode should behave the same way as any other 512n drive from OS point of view.

Apologize,as I was sleepy last time,I forgot,there is 1 possible hack for drives over 2TB to make them accessible(as data drive) for Windows XP,but maybe I forgot,because I did not tested it yet,but theoretically U can format a drive over 2TB as Superfloppy(no MBR nor GPT,single-partition only starting directly from the beginning of the disk instead of partition table),but most partition managers do not offer the option,but for example Rufus can do this,so I fix myself,maybe it has meaning to list 512e drives over 2TB to be formatted as Superfloppy,but I did not had the opportunity to test this,thus I cannot confirm,this worx,but sure I will test this,then I will share the results.
The other way-hybrid MBR+GPT in 1,or 2nd MBR after the 1st 2TB fooling the OS,the other part is another disk,or so,cannot be done in standard partition manager,U need some special tool for it,so if Superfloppy will work,it will be a simpler way to make Windows XP c over 2TB.

Sabina_16bit. wrote on 2025-02-24, 12:13:

Apologize,as I was sleepy last time,I forgot,there is 1 possible hack for drives over 2TB to make them accessible(as data drive) for Windows XP,but maybe I forgot,because I did not tested it yet,but theoretically U can format a drive over 2TB as Superfloppy(no MBR nor GPT,single-partition only starting directly from the beginning of the disk instead of partition table),but most partition managers do not offer the option,but for example Rufus can do this,so I fix myself,maybe it has meaning to list 512e drives over 2TB to be formatted as Superfloppy,but I did not had the opportunity to test this,thus I cannot confirm,this worx,but sure I will test this,then I will share the results.
The other way-hybrid MBR+GPT in 1,or 2nd MBR after the 1st 2TB fooling the OS,the other part is another disk,or so,cannot be done in standard partition manager,U need some special tool for it,so if Superfloppy will work,it will be a simpler way to make Windows XP c over 2TB.

For XP, using an SSD makes more sense to me (your use cases may differ, of course). For extra storage, a NAS is an option. SMB performance is not that great under XP, but it will allow one to sidestep the disk size limitation.

Another option is using ISCSI to create and export <2.2.TB volumes. It might be faster than SMB under XP (I have not tested) especially if using a NIC that supports ISCSI in hardware (no idea if any if those have XP drivers). Such a NIC could also be used to boot a system from an ISCSI volume.

EDIT: There is also the option of using a high performance SCSI card in the XP machine and building a machine running FreeBSD and using it as a storage server by leveraging SCSI target mode. People on Vogons have done this. It gives good performance, AFAICR.