Slashdot Mirror
Seagate Barracuda V Serial ATA Drive Reviewed
Mike Parsons writes "Andrew and Adam over at Explosive Labs have a nice review up on the Seagate Barracuda V, one of the first production Serial ATA drives. Keep in mind, Generation 1 of Serial ATA was not meant to be a 'incredible performance jump.' Rather, its intended purpose was to make the industry transition seamless to allow time to mature the future generations of SATA. Generation 2 and 3 of SATA show more promise for those interested in performance, as white papers behind them gives you the nice fuzzy feeling for speed!"
The problem with parallel data transfer is that, if you have lots of data channels running at the same time, you have to synchronise the arrival of all this data. It's very difficult to do this at high speeds (if you look at your motherboard you'll probably find a few places where the track wiggles back and forth to synchronise the arrival of data).
In recent years, it has become possible to run data connections at very high speeds - but only when you have only one data line. A USB 1.0 connection is comparable in speed to an ECP parallel connection, and there are far faster serial technologies nowadays.
Like car accidents, most hardware problems are due to driver error.
This is one reason why SCSI is so much faster/more expensive; all scsi controllers have this functionality so throughput is maintained even when the parallel data is clashing.
Whilst serial is theoretically slower than parallel, by removing these synching issues you can guarantee better performance in consumer-priced hardware. At the server end, SCSI will remain as price is less important than performance, and as I said, parallel is still more efficient if it has a decent sych algorithm *on board*.
I'm not so much interested in the performance advantages of S-ATA, rather the fact that it finally kills off ribbon cables. It must be the most limiting factor inside any desktop PC. In my tower I have trouble making even long cables reach drives at the top of the case, so they have to be mounted halfway down. In my Shuttle XPC the cables are shorter, but even they have to be 'rounded' and routed around clips to reach the combo drive without taking up all the space inside. Other people complain about the airflow restrictions several ribbon cables cause inside a machine.
In short, I don't care that (Gen-1) S-ATA starts at 150mb transfer instead of 'older' 133mb. I care that it makes building a PC easier, more space inside future barebones machines and PC manufacturers can use more interesting cases than the usual rectangular stuff. I'm excited about the possibilities it offers right now.
insignificant sig
Anyone know why this was implemented? The article (now /.'ed) doesn't explain the reasoning, just that it exists. Why get rid of the old MOLEX? Since an adapter is included with the drive it doesn't seem that there are any new voltages required. What's the deal?
Is this just another one of those PITA upgrades?
I always thought parallel was faster
:-)
:-)
Yes, provided they both run on the same clock speed. In this particular case they're not.
When you ramp up the clock speed of the parallel bus you get all sorts of problems (synchronisation issues, multiple wires affecting each other's capacitance, inductivity and such). One way of avoiding those problems was UltraATA's 80 wire IDE cable. And that came with increased price tag, and didn't ultimately solve all the problems, it just postponed them for a generation or two.
The other way was to abandon parallel all the way and go serial. Since with serial (one pair of wires) you don't get any above mentioned problems you can ramp up the clock much higher, and thus get better thrhoughput, although you're transfering just one bit at a time.
At first it sounds counter-intuitive, but it just goes to how much intuition is worth.
The Seagate drives may be a tad slower, but if you want to build a home multimedia server that will sit in your living room, they have the benefit of being unbelievably quiet.
At 24dB, you have to put your ear to a Barracuda drive to hear it, whereas the Western Digital drives put out a whopping 39dB!
Alright so far most of the posts are misguided, so I'll answer a few questions. But first, this was mentioned in the slashback that is still on the front page. Please post any corrections.
1a. Yeah!, faster drives.
No. Find me a drive that can use PATA-100 to the max let alone PATA-133 and I'll be a very happy customer. Current drives do not use current capacity, the only time the bus becomes an issue is where you are bursting from the drive cache to the controller, which is not enough to really worry about except in certain situations (The same data is read continuously).
b. Yeah!, Faster drives.
No. Why a second point? The first point dealt with bandwidth. This one is for latency. Please remember that most SATA controllers on motherboards, etc (atm at least) are actually a bridging chip to a PATA controller. This incurs a slight latency delay. If you do a lot of small file accesses you will be effected.
2. Whats the point we already have enough speed?(ie I already know 1.)
a.The point is smaller cabling, making cases less cluttered, meaning better cooling, and easier to keep wiring neat and out of the way. Why no use rounded cables? You didn't think the cables where a ribbon shape for looks did you? The cables are meant to be ribbons to reduce the interference between each pair (limits it to the pair on each side). Rounding the cables causes all pairs to interfere with each other resulting in a much shorter maximum cable length before there are too many interference errors on the bus.
b. Point to point cabling, knock a cable loose, or have a misbehaving drive and you loose one drive. With PATA you can loose 2, or with SCSI you can loose up to 14 (Wide, not typically a problem on modern auto-terminating devices)
c. You can disconnect a drive from a powered controller without risking blowing the controller chip (Possible with PATA). Making removable hard drive cradles finally usefull on ATA systems.
d. Longer in-spec cable lengths. PATA cables (Sorry I forget the length off hand) can't reach the top 5 1/4" drive bay in a full tower case. SATA cables can. Why not use longer PATA cables? Cables longer than PATA spec tend to suffer badly from interference based errors, resulting in a lot of resends on the bus, sometimes causing bad data on drives.
3. The performance isn't what I hoped (or a WD JB is faster)
This drive isn't intended to be the fastest on the block, it is meant to be quiet. Seagate drives have the new fluid bearings, they haven't been the fastest on the block for a while now, what makes you think this one would be different?
I personally think this is a good drive to be first to SATA, as the people likely to appreciate the quiet drive would also desire the better air flow offered by smaller cables, meaning slower case fans, and a quiter PC.
4. Why don't they compare a PATA Barracuda V vs a SATA Barracuda V.
The PATA has a 2mb cache the SATA has an 8mb cache (and a slightly faster access time, by 0.6ms). They aren't directly comparable, the SATA version is obviously aimed to be the top of the line model.
5. The power connecters. The Barracuda V requires the same power voltages that current PATA drives do, so an adapter works fine. However it was intended to supply drives with multiple voltages (such as 3.3v, 5v, etc) so that the electronics can use a different voltage than the drive motors, reducing the power consumption of the electronics, and therefore the heat output. Some drives get very hot, and every little bit helps.
I think thats all.