2.5 Inch Hard Drive - New Hitachi High Speed Experience and Questions

I have 5 Hitachi drives that I use for cloning my internal SSD - they're fine disks.

SSDs, of course, are already faster than spinning drives - so are Hybrid drives (with a bit of SSD mixed with a large spinning platter). There are, of course, enterprise drives that run faster than 7200rpm and I think that you can expect those speeds to come to the consumer in the future. But as great as SSDs are, I don't see them replacing spinning drives for servers, etc. It's not that they're not durable - they're still just too expensive for the capacity needed when compared with SSDs.

Your Hitachi is probably perceivably faster because of several factors, advanced technology and a higher spin rate. Glad that you like it!

Clinton

MacBook Pro (15-inch Late 2011), OS X 10.??, 16GB Crucial RAM, Crucial M500 960GB SSD, 27” Apple Thunderbolt Display

The increase in speed could be a few things:

1. The fact that it's an advance format 4K sector drive.

2. The increased rotational speed.

3.. Possibly compression (speculation on my part) but on the fly data compression

Item 3 is something some SSD manufacturers were considering. If I understand it properly data would be compressed on the fly before being written to an SSD. For an SSD it's a bigger deal because it cuts down on the number of write cycles which are limited, plus it allows manufacturers to advertise the drive as being bigger because they can squeeze more bytes of compressed data onto the same surface.

Now if you take this little theory of mine and apply it to a regular HD, you end up storing more data per sector than you normally would. For example, lets say you write one sector of data to your old Fujitsu and it took 1 ms. If they could compress data on the Hitachii, then maybe they could write twice as much in the same time. The result would be what appears to be a much faster drive.

I see no reason why an HD manufacturer wouldn't do this. Maybe they are already, but if this was a newly implemented feature it could explain the 2:1 data rate ratio.

SSDs don't particularly impress me. They're a great asset if you constantly use lots and lots of heavy drive I/O, but most people don't. I had a 120G SSD in one of my systems and found I ended up having to "manage" it all the time. Not enough space...go in, delete this, delete that, backup this, backup that. It got tiresome. It was like I was living in the '80s again. Most applications once loaded are cached in RAM and after a first start most activity is right out of RAM anyway which is faster than an SSD. I don't hate SSDs I just think maybe they're being a bit over-hyped for what they do and how long they last (another story).

I don't know about formatting but I think that with 512e mode emulation it just allocates a 4K junk and then sequentially fills it in with 8 512 byte chunks of data, leaving any odd left overs untouched. It really shouldn't affect anything because the block size used by the OS is usually 4K anyway. The only things that would be block sensitive were things doing low level raw access where they deliberately assigned a block size of 512.

@Fred1956:

How's the power consumption on that drive? Does it cause the fans to run more?

The reason I ask is that 7200RPM drives typically consume more power, which in turn causes the supply to be in use more which in turn causes the system to heat, hence fans come on.

There are 2 main reasons your drive is faster, the most important is the 300% increase in Areal Density of the drive (more data storage in the same physical space means that everything is closer together), the second is the 35% increase in rotational speed. The rest of the things mentioned are minor in comparison.

Thanks for checking the power info Fred. That drive sounds like it would make a great HD part of a Fusion drive, and I may just do it.

Thanks.

What's the exact model of your MacBook, and how fast is the SATA interface on it?

Fred1956 wrote:

It's a mid 2009 year model. According to MacTracker the interface is 3Gb/sec which is SATA II I believe.

Sata2 on the HDD cable, possibly Sata1 on the optical drive connection (which can be fixed by changing the cable)

That HD is inside the realm of SATA I, which is pretty impressive.

From Wikipedia:

A lot of people mistakenly think of HD speed as the cache to logic board data rate which will often be that of the interface, but in this case it's possible that the transfer rate from the HD platters to the system could actually be bottlenecked by a SATA I system - imagine that!!

Your speeds are a touch low but in the ballpark.

The fastest SSD's (under test conditions) reach about 550MB/s

Functionally, it's pushing the limit…not quite there, but pushing the limit. From a cost comparison with SSDs it's tens of dollars per hundreds of gigabytes vs. hundreds of dollars for SSDs.

One thing I've never understood is why hard drive manufacturers don't use bigger caches. The 32M is by todays standards, for consumer drives, large, but it's really tiny. Why not 1GB or something like that. Unless someone was really hammering the system with new application launches it would basically cache the core OS in most cases. How many people are really hammering their systems with gigabytes of data transfers over a period of minutes? Not too many, I would think.