nx8220, PATA and SATA devices....????

PATA = Parallel ATA interface. What you see in many desktops - the wide 80-pin gray cable. It has a maximum throughput of 133 MB/s.

SATA = Serial ATA interface. The new standard that is quickly replacing the clunky PATA interface. It has a maximum throughput of 150 MB/s (actually, SATA's newest technology in the desktop world is SATA 3G which has a max throughput of 300 MB/s, but not yet in laptops).

That said, there really isn't much difference between the PATA and SATA interface as far as performance goes. Very, very rarely does a computer take advantage of even 133 MB/s throughput, so going to 150 absolutely does not increase performance by 12 percent as the numbers would indicate. In fact, you would be very hard pressed to see any difference in performance. Currently the only real advantage of SATA is that the cables for SATA are thinner (b/c there are only 5 wires instead of 80), the drives are hot-swappable and the cable can be longer than PATA, but those are not really an advantage for laptops. Don't worry about PATA vs SATA, worry about spindle speed. You'll want at least 5400 RPM (though 7200 RPM carries noticeable improvements in performance). What you have referenced will be a very good laptop and should give you more than enough performance.

The real issue isn't SATA -vs- PATA, it is that both the HDD and the CD/DVD share a single PATA port, while the two built in SATA ports in the Sonoma chip set sit idle.

The only time this makes a difference is when you are transferring data between the HDD and the CD/DVD. (Burning or ripping CD/DVDs.) Each device has to share the 133 MB/s (or is it 100MB/s?) bandwidth with the other, so the PATA port becomes a bottleneck.

The SATA ports are built in, and the SATA cables are cheaper, so why did they do this? I can think of two possible reasons. (1) SATA HDDs in the 2.5" form factor weren't readily available when the laptops were being developed, or (2) PATA HDDs were less expensive.

Here are some more tidbits to wet your curiosity. When an HDD is idle it 'reads ahead', and puts the data into the 8MB buffer. If the computer issues a read command for data that has already been read into the buffer, the data is transferred across the bus at the maximum speed the bus can support. If the computer issues a command for data that is not in the Buffer, the HDD has to seek to the track (~0.5-7ms) and then the data comes off the head and into the buffer at a rate between 30MB/s and 80MB/s, depending on the radius. The data rate is higher at the outer zones, and drops progressively, in steps, towards the inner zones.

Also, HDDs are much better at doing reads than doing writes. One reason is that there is no equivalent to the ‘read ahead’ for a write operation. You can’t write data from the buffer to the HDD when you haven’t received the data from the computer yet! Also, HDDs have less hardware automation in the write path than they have in the read path. In other words, the embedded processor on the HDD has to get involved in every write command, but there is usually hardware that will automatically transfer data on a ‘cache hit’ for a read command.

If you are burning a CD, you cant burn even 133MB/s to a disk. If you are ripping a CD to your hard drive, You cannot rip 133MB/s so i doesn't really matter.

The only reason for laptops that you would want SATA right now are:

1) For bragging rights...
2) If you have 2 SATA hard drives in your laptop & will be using them in a RAID configuration which is advanced stuff, or If you were going to be moving files between the 2 hard drives in the laptop. And even still its not going to be much faster...

Trust me on this. I've been around the forums for along time & have been working with laptops for over 10 years and desktops even longer....

Yeah... Well dont get me wrong.... SATA is great. But the technology has not matured in laptops were its worth it. Offering them in systems is the first step...

From a strictly numbers point of view, you can't really tell what the bottom line is without knowing more about the CD/DVD transfer rates. I can't say because I don't know. If anyone does know, please chime in. Specifically, how fast can a CD/DVD drive read data from the media, and how fast can it write it. Of course, this will depend on the speed of the unit, e.g. 4x, 12x, 24x, etc., but for our purposes, some ball park figures would be fine.

In the absence of that information, I agree with what Teck wrote.

[edit] Here is more stuff. Gen II SATA will be coming out in the very near future. This technology will actually give a noticeable improvement over PATA. It brings two noteworthy improvements. First, 3Gbps transfer rates. This translates to 300MB/s data transfer rate on the bus. Second, NCQ, which stands for Native Command Queuing. This feature allows the computer to give the HDD up to 32 separate commands all at once, and lets the HDD figure out which one to do first, second, third, etc. The HDD can look at the current position of the head, and do a command that is near by, before doing one that is all the way across the disk. It also lets the HDD start on the next command while the data for the previous command is still being transferred from the buffer to the computer. This capability has been around in SCSI and Fibre Channel HDDs forever, but is just now trickling down to SATA.

In order to avoid confusion, they use the term Gen II SATA to refer to a SATA HDD that supports NCQ. A Gen II SATA HDD can be either 1.5Gbps or 3Gbps. So if you want to refer to an HDD that supports NCQ and has a 3Gbps data rate, you would call it a SATA Gen II, 3Gbps HDD.

well i am right because even on a 48x cdrom drive you can read only 24MB/s v.s. the 133MB/s that your hard drive can do....

Teck,
Given those numbers, you are absolutley correct.

Oops, I just checked the transfer rate of the 60GB, 7200rpm HDD that came in my NC8230. (hts726060m9at00) It's an Ultra ATA/100. In other words, 100MB/s.

I also appreciate the explanation. I'm still confused about the IDE controller and if it's the same controller for PATA and SATA drives. I was told that since it's the same controller, then there were no advantages to SATA other than what was just explained, especially the information about transfer rates, buffers, etc.

Right... I just noticed that... Nice catch... But even still its not worth it...


1) SATA-II is just appearing in desktops so for laptops maybe another 3+ years? I think it was about that long before they put SATA-I in laptops...

2) It should be the same. I can find & check the service manual to make sure...


1) The IDE controller is not the same for the PATA & SATA... If a laptop is using both then they are both different controllers.... (Or atleast as far as i know & i think they would have to be)...

2) Your right, The RPM & Buffer size of a drive are whats important. But for power reasons i ALWAYS go for the 5400RPM in laptops because the battery lasts longer...

IDE and PATA are two ways of saying the same thing. The Sonoma chip set has one PATA and two SATA ports (controllers) built in. When you buy the chipset you pay for all 3, whether you use them or not. Internally, they are each connected (one would assume) to a high speed bus that can handle many times the bandwidth of any individual port.

Now for a personal rant. (My bad, please excuse me.)

If I was designing the motherboard for a laptop and was forced by circumstances to use PATA peripherals, I would leave a little space on the board for a SATA connector, and wire it up to the chip-set anyway. It wouldn’t add a penny to the manufacturing cost.

I don’t know of anyone who has actually opened up their unit and looked for an empty mounting hole pattern for a SATA connector, but I wouldn’t be at all surprised if there is one there. In fact, I would loose a lot of respect for HP Engineering if there isn’t at least one.
[end of rant]

On SATA controller –vs- PATA controller -

The ‘Host’ end of a SATA controller is designed to look exactly like the Host end of a PATA controller. In other words, the computer is supposed to be able to use the same software (BIOS) to talk to a SATA HDD that it uses to talk to a PATA HDD. But internally, SATA and PATA controllers are very different. This gives SATA backwards compatibility into the huge installed base of PCs.

However as time goes on, new features will be (are being) added to SATA that will not be available on PATA.

I wouldnt leave a space for something like that in a laptop that way end users don't try to modify there systems and use their HP warranty to get it fixed... However I'm sure there is an EMPTY hole pattern for a SATA connector on a few systems...

And your right with SATA we will be able to have MASSIVE amounts of cache on the hard drive... Thats one thing im looking forward to...