Harddrive questions

What is a good hdd or do I already have one.
I just dont want my hdd to the reason if I start lag up.
I really don't mine load times.
Biggest thing i be doing is gaming.
Crysis,cod 4 , and so fourth

 

That WD 5400RPM HD is fine for most uses. Of course, upgrading to a denser, 7200RPM, or SSD HD would improve the overall speed of your computer.

 

Form what you say you do and don't mind load times no reason to go spend money unless you have too much. Certainly not top notch but not a bad one either for size and 5400rpm. Here is a link so you can see some numbers of what's out there to compare.

 

I was wondering, what about an external hdd? Aren't there fast ones (faster than built in) through firewire/USB2?

 

Regardless of how fast your external HD will be, if it is connected to your machine via USB or Firewire, it'll be bottlenecked by the connection, and as a result not be as fast as your internal HD.

You might experience improved performance compared to your internal HD if you got an eSATA expresscard external HD, or a networked gigabit ethernet external HD, but those are more expensive than USB/Firewire, especially the reliable ones.

 

In terms of transfer speed the USB 2 or Firewire interface is hardly any bottleneck. USB 2 can transfer up to 60 MB/s and Firewire can be even faster. A normal desktop harddrive wouldn't even peak at such rates. However, one might experience an increase in latency, but that should be negligible with the mechanical latency.

 

USB 2.0 60MB/s? Not goin to happen in this lifetime!

 

On paper, USB 2.0 should be able to reach speeds of up to 480Mbit/s. However, as the USB interface relies heavily on the CPU, and the interface itself is not the same as the native interface of the HD (therefore the HD enclosure has to convert the SATA signals to USB), the actual throughput is usually around 10-20MB/s, usually much lower. Firewire is limited in the same way as it too has to convert the interface.
As a result, USB and Firewire interfaces can be seen as a major bottleneck to external devices.

eSATA is faster because it is basically SATA. Gigabit ethernet NAS (the good ones) is faster because it is just so expensive that the developers actually put some effort into making it decent.

 

Guess you learn something every day. Didn't realize that the conversion was such requiring.

However, I'm do not agree with the part where you claim that the speed of USB2 is usually lower than 10-20MB/s (10MB/s) for an external drive and limited at such rates by the interface. For example http://www.xbitlabs.com/articles/storage/display/fujitsu-handy-120gb.html in this article we can see that the difference between highest and lowest speed is significant, thus implying that it's mechanical rather than interface limited.

To answer myself, it doesn't look like you can gain much with an external drive, unless you connect this to a FW800: http://www.xbitlabs.com/articles/storage/display/wd-mybookpro.html

 

XCan I have to agree with Budding his 10MB to 20MB sustained transfer is close or maybe to generous. My 7200rpm external 12.8MB sustained transfer it does not graph from high to low it is almost flat on HDTach not like an internal does, starts at 50MB goes down to 25MB.That indicates it is not the HDD that is slow it is the bus. Your first link. so in a benchmark they can get almost 40MB/s? Yea they set up the conditions for the purpose of testing. Not real world. I think you would have to agree my WD 7200 is capable of about 40MB/s sustained internal so why am I getting only 12.8MB/s? Answer USB and it's overhead. Forget your benchmarks except for comparing HDD's. By the way my USB stick 11.9MB/s.

 

I don't doubt that the speed is lowered by the interface (anymore). But I'm not convinced that the pure transfer speed through it is the major limiting factor, given that the mechanics and the index is in the logics of the hdd.

We can look at http://www.xbitlabs.com/articles/storage/display/25inch-hdd-250gb.html . It seems to vary a bit too much between situations for it to be it. I dunno, maybe the OS needs to communicate with hdd more than I thought.