UDMA, SATA, IDE: how many drives can I put in my computer?

Subtitle: Hey, HD sales &marketing: pick a name and figure out how you want to abbrieviate it, you *$##*$&@.

Here's how you write serial ata: SATA/xxx (where xxx is max speed, eg. SATA/150 is SATA @ max speed 150 MillionBytes per second

this post (mirror), Dec 28 2004, is helpful on the "Hard drives - UDMA vs. SATA" question

For example, (1) the Seagate Barracuda 7200.7 120GB SATA150 or (2) the Seagate Barracuda 7200.7 120GB UDMA100?

Currently there is little difference between the two. Neither saturate the bandwidth available to them. You'd be far better to look at the performance of both drives in terms of:

- seek time (lower the better); - cache (bigger is better) ; - spin speed

If all things are equal, I'd go for the SATA drive as the cable is a lot smaller and therefore makes for a tidy inside of a PC

Is it possible to add a 3rd or 4th drive to my 8200?

8200 is Ultra ATA/100 (?): currently has 2 drives, IDE cable (not SATA cable)
ATA-66 or ATA-100 UDMA.

What about the XPS?

XPS Gen 2: (current technology, as of Feb 2005, is Serial ATA, e.g. Serial ATA-150 aka SATA/150)
Drive is "Interface Type: SATA/150"

IDE Controller Model: Intel(R) 82801EB Ultra ATA Storage Controller

"one of the most awaited new features of Intel's 875 chipset is the integrated Serial ATA controller... the Serial ATA logic was integrated in the southbridge (ICH5). Thus, there is no longer any need for an additional chip or even a Serial ATA PCI controller card from Promise & Co. What remains is the UltraATA/100 controller with two ports, which allows you to run four IDE ATA drives."

It's not just the new interface that Serial ATA brings, but the possibility of operating six ATA drives (4x UltraATA, 2x Serial ATA).

From the intel board spec:
Integrated Serial ATA Host Controllers (2 SATA Ports)
— Independent DMA operation on two ports.
— Data transfer rates up to 1.5 Gb/s (150 MB/s).
— RAID Level 0 Support (ICH5R Only)
Integrated IDE Controller (2 IDE Ports)
— Supports “Native Mode” Register and Interrupts
— Independent timing of up to 4 drives
Ultra ATA/100/66/33, BMIDE and PIO modes
— Tri-state modes to enable swap bay

According to the XPS manual, you can have either
Configuration 1: Two IDE hard drives
Configuration 2: Two Serial ATA hard drives
Configuration 3: Two Serial ATA drives in either a RAID level 0 configuration or a RAID level 1 configuration PLUS one IDE hard drive

Interesting note: The Serial/Ultra ATA Combo Card supports
Serial ATA data transfer rates up to 150 MBps and Ultra ATA data transfer rates up to 133 MBps.
(i.e. Serial ATA trumps/ better than Ultra ATA)

The chief choices are either going to be IDE or Serial ATA:

The 8200 manual seems to indicate your choice is two dives, that's it. You could probably add a Serial ATA controller card
to a PCI slot if you wanted to add two SATA cards, but they'd probably run at IDE speeds anyway.

This is misleading, because right now I've got a SATA drive connected to the SATA port, and two IDE drives on the IDE cable,
and they're all running happily together, and all accessible under Windows XP.

(one of those IDE drives is old and using FAT instead of NTFS as well).

Ultra-DMA aka Ultra-ATA aka Ultra33 and Ultra66 aka Ultra DMA/33 or ATA/33 hard drives

Ultra DMA (UDMA) is the latest version of the ATA bus mastering Direct Memory Access (DMA) protocol.
It increases the maximum data transfer rate of the ATA bus from 16.6 Mbytes/sec to 33.3 Million Bytes per sec [ commonly, but incorrectly, written as "MB/s"].
The ATA/ATAPI 4 specification also introduces error checking, which ensures data integrity at the higher speeds.

Note: In common parlance, drives that use Ultra DMA are often called "Ultra ATA/xx" where "xx" is the speed of the interface.
So, few people really talk about current drives being "Ultra DMA mode 5", they say they are "Ultra ATA/100".

Because the Ultra DMA protocol is designed to work with legacy application PIO and DMA protocols, it can be added to many existing computers by installing an Ultra DMA/33 PCI (Peripheral Component Interconnect) adapter card. Ultra DMA uses the same 40-pin IDE cable (Integrated Drive Electronics interface cable) as PIO and DMA.

The ANSI name for IDE is Advanced Technology Attachment (ATA).


ATA-4: This standard implements Ultra DMA, aka Ultra-ATA. At this time, hard disk mechanics had well exceeded the data transfer rates possible through the interface. This standard allows data to be pushed twice per clock cycle, thus doubling the bandwidth to 33MB/sec. Hence this is often described as ATA/33.

ATA-5: The bandwidth was doubled again, to ATA/66. Note that to use hard disks in this mode, an 80 line wire is required, rather than a standard 40 line wire.

ATA is the name of the overall specification. We're currently at ATA-7.

ATA-7 includes:
SATA-1 and others.

read more about SATA ; tom's hardware article


Further Quotes:

"Ultra DMA/133/100 (Ultra ATA133/100) cards will enable the latest high performance hard drives to operate at their best. This high performance is needed to get the maximum performance from 7200RPM Ultra DMA/100/133 or Ultra DMA/66 drives. If you need performance for Digital Video (DV) capture and editing or Digital Audio workstation recording or just want the fastest bloody computer you can have then an Ultra DMA/100 controller card and fast hard drive(s) are essential. Of course you will need the best Ultra DMA 133 cables you can get as well. Ultra DMA 66 , 100 or 133 will not work without the correct cables.
No [UltraDMA hard drives] can put out 133MBps. The fastest 7200 RPM UltraDMA/100 drives can reach a maximum "sustained" transfer rate of less than 42MBps, and that's only on the fastest part of the disk. See Storage Review's explanation of "Internal Sustained Transfer Rate (STR)" for a better understanding of drive performance. The only way to even approach a sustained rate of 100MBps is using a "striped" RAID setup. Put three or four high performance drives on a RAID card and you can have real 100MBps sustained data rates!
:: source

NOTE: should say "you can get close to 100 Million Bytes per second data rates!" And it's probably not true even then.

" Serial ATA's dedicated 150 MB/sec [Editor: Actually, 150 million Bytes/sec = 143 MB/s] maximum performance per device, ... the bus already has room to spare when today's (Nov 2003) best-of-breed drives are hard pressed to deliver 100 MB/second."
"It should be noted that while data rates of 150MB/sec are quoted for SATA (Dec. 2004), with much larger figures expected soon, this is not the speed that a drive will actually transfer data. This is because the limiting factor on disk throughput is its mechanics, not the interface. Hence modern drives, even those using SATA/150, are unlikely to yield transfer rates much higher than 60MB per second"

42,000 KB/s (aka "42 MB/s") =about 336 mbps (megabits per second)

By way of comparison, your local network is 100 mbps; downloads are typically around 1.1 mbps on a 1.5 mbps DSL connection.

USB 2.0 has a 480 mbps data transfer rate. Better than network speed, much poorer than internal drive speeds.

"With data transfer speeds up to 150MBytes/sec ([Editor: actually 143 MB/s, or 1200 mbps (1,200,000,000 bits per second)] over two and a half times the speed of USB 2.0), Serial ATA has quickly become the gold standard for high-speed data transfer. "

"[so-and-so card] is compliant with Serial ATA specification (revision 1.0) and allows you to connect your existing Ultra ATA 133/100/66 hard disk drives to the fast Serial ATA host adapter."

Your DVD burner is E-IDE.

2003: "Beginning this year, the storage industry is transitioning from the legacy parallel ATA interface to serial ATA.
The serial ATA (SATA) final 1.0a specification was released February of this year."