Storage - Revision history

Douglar: /* Storage After IDE/PATA */

2026-03-31T15:58:51Z

‎Storage After IDE/PATA

Douglar: /* Storage After /IDE */

2026-03-31T15:49:28Z

‎Storage After /IDE

Douglar: /* Post PATA Connectors */

2026-03-31T15:37:57Z

‎Post PATA Connectors

Douglar: /* Post PATA Connectors */

2026-03-31T15:37:15Z

‎Post PATA Connectors

Douglar: /* Post PATA Connectors */

2026-03-31T15:35:09Z

‎Post PATA Connectors

Douglar: /* NVME */

2026-03-31T15:31:14Z

‎NVME

Douglar: /* Storage After PATA */

2026-03-31T15:30:54Z

‎Storage After PATA

Douglar: /* Common IDE Categories */

2026-03-31T15:15:50Z

‎Common IDE Categories

Douglar: /* CF (Compact Flash) */

2026-03-31T14:55:47Z

‎CF (Compact Flash)

Douglar: /* CF (Compact Flash) */

2026-03-31T14:54:19Z

‎CF (Compact Flash)

@@ Line 300: / Line 300: @@
 * Cannot be used as a boot device without UEFI firmware support and Operating System support
 * Microsoft provided Windows 7 drivers, and community created Windows XP drivers
-* Linux GRand Unified Bootloader (GRUB) has support for NVME devices
+* Linux GRand Unified Bootloader (GRUB) has boot support for NVME devices
 === Post PATA Connectors ===

@@ Line 269: / Line 269: @@
-== Storage After /IDE ==
+== Storage After IDE/PATA ==
 === SATA I ===
 * SATA I controllers worked in "legacy mode".
 ** The send and receive commands through x86 I/O space (0x1F0, 0x170) like classic IDE drives.
-* The controller captures the commands from the emulated ports put them into FIS (Frame Information Structures) for the SATA device.
+** The controller captures the commands from the emulated ports put them into FIS (Frame Information Structures) for the SATA device.
-* Some early SATA devices were often PATA devices with a built in SATA bridge
+* SATA I storage devices accept ATA commands over FIS and processes them like legacy PATA.
-* SATA devices didn't commonly implement TCQ (Tagged Command Queueing) because TCQ for PATA was not particularly efficient.
+* Some early "SATA" devices were simply PATA devices with a built in SATA-PARA bridge
 === SATA II ===

@@ Line 307: / Line 307: @@
 * mSata (aka Mini Sata) was common between 2009 to 2014
 ** Devices were most commonly 30mm x 50.95mm
-* M.2 Sata (aka NGFF, Next Gen Form Factor) arrived in 2013 and are usually:
+* M.2 Sata (aka NGFF, Next Gen Form Factor) arrived in 2013.  Common device sizes are:
 ** 2230	- 22 × 30 mm	Small laptops, embedded systems
 ** 2280	- 22 × 80 mm	Most common SSD size
-* M.2 has 3 different key pattern
+* M.2 has 3 different key patterns:
 ** B key, single notch on left, usually SATA
 ** M key, single notch on right side, usually NVMe with 4 lanes of PCIe

@@ Line 305: / Line 305: @@
 * SATA was introduced with Sata Data & Power pair connectors that replaced PATA 40 pin ide header and 4 pin molex power
-* mSata (aka Mini Sata) has a 30mm edge connector and was common between 2009 to 2014
+* mSata (aka Mini Sata) was common between 2009 to 2014
-* M.2 Sata (aka NGFF, Next Gen Form Factor) arrived in 2013 and is usually:
+** Devices were most commonly 30mm x 50.95mm
 ** 2230	- 22 × 30 mm	Small laptops, embedded systems
 ** 2280	- 22 × 80 mm	Most common SSD size

@@ Line 304: / Line 304: @@
 === Post PATA Connectors ===
-* SATA was introduced with Sata Data & Power pair connectors
+* SATA was introduced with Sata Data & Power pair connectors that replaced PATA 40 pin ide header and 4 pin molex power
-* mSata (aka Mini Sata) 25mm edge connector was common between 2009 to 2014
+* mSata (aka Mini Sata) has a 30mm edge connector and was common between 2009 to 2014
-* M.2 Sata (aka NGFF, Next Gen Form Factor) appeared in 2013 and is usually 22mm wide compared to mSATA which was 30mm.  Has 3 different key pattern
+* M.2 Sata (aka NGFF, Next Gen Form Factor) arrived in 2013 and is usually:
 ** B key, single notch on left, usually SATA
-** M key, single notch on right side, usually NVMe PCIe up to x4
+** M key, single notch on right side, usually NVMe with 4 lanes of PCIe
-** B+M key, two notches, can be SATA or NVMe PCIe up to x2
+** B+M key, two notches, can be SATA or NVMe with 2 lanes of PCIe
 == Notes not worked into the main document yet ==
 * MBR partitioned storage devices are limited 2TB.  Larger devices require GPT (GUID Partition Table).  GPT use requires operating system support (Vista SP1, macOS 10.4, Linux version 2.6.x ).  Booting from GPT requires UEFI support.
 * VIA8237 and VIA8237R SATA controllers are incompatible with SATA-II and SATA-III storage unless the devices can be configured to force SATA 1 operation.  The VT8237R Plus is not affected.

@@ Line 269: / Line 269: @@
-== Storage After PATA ==
+== Storage After /IDE ==
 === SATA I ===
-SATA devices attached to a controller in legacy mode do LBA addressing & the same ATA commands and receive those commands through x86 I/O space (0x1F0, 0x170) just like classic IDE drives from 1980's. The controller captures the commands from the emulated ports put them into FIS (Frame Information Structures) for the SATA device. SATA devices didn't implement TCQ (Tagged Command Queueing) because TCQ for PATA was not particularly useful.
+* SATA I controllers worked in "legacy mode".
 === SATA II ===
-SATA II (>= 2004) devices support AHCI Mode (Advanced Host Controller Interface). When in ACHI mode they do LBA48 addressing with a slightly updated ATA command set, but the commands are sent directly through FIS to the SATA device, no more legacy PATA port emulation, reducing latency. SATA devices from this generation often support NCQ (Native Command Queuing) at a depth of up to 32 commands in flight.  Some early VIA SATA I controllers only work with SATA II devices that can be configured to force legacy mode.
+* SATA II (>= 2004) devices support AHCI Mode (Advanced Host Controller Interface).
 === SATA III ===
-SATA III offers some refinements of the AHCI command set, but mainly raised the throughput from 3GB/s to 6GB/s which was important for SSD SATA devices.  Some SATA III devices have trouble falling back to SATA I controllers operating in legacy mode.
+* SATA III offers some refinements of the AHCI command set, but mainly raised the throughput from 3GB/s to 6GB/s which was important for SSD SATA devices.
 === NVME ===
-NVME devices are native PCIe devices that do no not support ATA or ACHI command sets.  That's why don't see cheap NVME - PATA bridges like you do with SATA.  NVME command set uses linear addressing with up to 64 bit addresses. NVME devices use memory queues implemented in pairs, a submission queue (ASQ) & completion queue (ACQ). Each queue pair is up to 65,535 commands deep, and there can be up to 65,535 queue pairs.  Eliminating ATA & ACHI and switching to in-memory queues provides extremely low latency compared to PATA or SATA. Having many queues is beneficial for VM hosts and for processors with many cores.
+* Common after 2018.
 == Notes not worked into the main document yet ==
 * MBR partitioned storage devices are limited 2TB.  Larger devices require GPT (GUID Partition Table).  GPT use requires operating system support (Vista SP1, macOS 10.4, Linux version 2.6.x ).  Booting from GPT requires UEFI support.
 * VIA8237 and VIA8237R SATA controllers are incompatible with SATA-II and SATA-III storage unless the devices can be configured to force SATA 1 operation.  The VT8237R Plus is not affected.

← Older revision		Revision as of 15:15, 31 March 2026
Line 43:		Line 43:

	More information about PATA ATA is available here: https://en.wikipedia.org/wiki/Parallel_ATA		More information about PATA ATA is available here: https://en.wikipedia.org/wiki/Parallel_ATA
−
−	~~'''SATA'''~~
−	* Common after 2004
−	* Early SATA devices were often PATA devices with a built in SATA bridge
−	* Bridges are commonly available today to connect PATA devices to SATA controllers & vice versa.
−	* Most native SATA devices support ACHI features such as NCQ, TRIM, better power management and hot swapping, but these features can be difficult or impossible to access when the device is attached through a PATA bridge.
−	* There are three common SATA versions: SATA I (150MB/s), SATA II (300MB/s), SATA III (600MB/s)
−	* There are three common SATA connectors: Sata Data & Power pair / mSata (aka Mini Sata) 25mm edge connector / M2 Sata (aka NGFF, Next Gen Form Factor) 22mm edge connector with two notches (B & M keys)
−
−	~~'''NVMe'''~~
−	* Common after 2018, not IDE, no longer uses ATA protocols
−	* Uses the same M2 connector as NGFF Sata, but uses different pins
−	* Connects storage directly to PCI-Express
−	* Cannot be used as a boot device without UEFI firmware support and Operating System support
−	* Microsoft provided Windows 7 drivers, and community created Windows XP drivers
−	* Linux GRand Unified Bootloader (GRUB) has support for NVME devices

	== BIOS Storage Limitations ==		== BIOS Storage Limitations ==

@@ Line 125: / Line 125: @@
 * Devices labeled "industrial" often work best for retro-computing, supporting the best response times & compatibility.
 * "Consumer" devices are often optimized for storing large images files and may not perform as well on random access work loads
 * While some CF devices support speeds faster than 133Mhz/UDMA6, those speeds are not accessible from a PC.
-* CF continued to grow the ATA specification through in 2010 with the release of the CF 6.0 standard
 '''Pros'''

@@ Line 130: / Line 130: @@
 '''Pros'''
 * Still very common and affordable
-* Most operate in "true IDE mode", so the devices have native ATA support & use inexpensive pass though adapters
+* Designed to operate as a PATA SSD in "true IDE mode", so the devices have native ATA support.  Connecting these devices to a 40 pin IDE header only requires an inexpensive pass though adapter.
 * Portable media that is easy to move between old and new computers
-* Rugged form factor that is difficult to damage
+* Rugged form factor that is sturdy and not prone to loss or electrical damage
 '''Cons'''
-* New industrial CFs are becoming less common from major brands
+* Compact flash is now a legacy product and new devices are less common than they were 15 years ago.
-* TRIM support on a CF is rare, making CF's less desirable for operating systems that support this feature
+* Some CF devices report themselves to be "removable media", even when in "true IDE mode", which can cause problems for Windows 2000 & XP installation.
-* Some CF devices report themselves to be "removable media" when in true IDE mode, which can cause problems when installing Windows 2000 & XP.
+* Few CF devices support ATA block transfer sizes > 1.  This can cause lower max transfer rates when compared with other devices that support block sizes > 1.
-* Few CF's support ATA block transfer sizes > 1.  This can cause lower max transfer rates when compared with devices that support block sizes > 1.
+* Very few CF devices if any support ATA TRIM, making them less desirable for operating systems that support this feature.
-* Pin28 issues on old boards.  Some pre 1991 systems experience video corruption with CF's https://www.vogons.org/viewtopic.php?p=1142705
+* Pin28 issues on old boards.  Some pre 1991 IDE controllers cause video corruption with CF's https://www.vogons.org/viewtopic.php?p=1142705
 === SD to IDE Bridges: ===