Just an idea, feel free to exhalt it or shoot it down....

 

I thought that it might make different hard drive deals more easily comparable if we all posted this simple ratio (# of GB/amount of money rounded to nearest dollar) in the thread title of every new hard drive deal.  My reasoning is that there is basically no difference in many of the drive parameters between most of the hard drives any of us would buy today.  All are SATAII, all are 3.5", and all are going to be from either the two reliable brands, WD and Samsung, or the two less reliable brands, Seagate and Hitachi (sorry Seagate, but you've been sucking it up lately).  Other drive parameters, such as the rotational speed and cache, could be posted in the thread.

 

For example, the thread title for the deal I posted today would look like:

 

[12.5] Samsung Spinpoint F1 1TB for $79.99

 

The ratio 12.5 is derived from: 1TB / $79.99 = 1000 GB / $80 ($79.99 rounded to the nearest whole dollar amount) = 12.5 GB/$

 

Comparing this to the next deal in the list:

 

2TB / $199.99 = 2000 GB / $200 (again, $199.99 rounded to the nearest dollar) = 10.0

 

So if I were causally browsing the Good Deals! forum, I would see the two topics as:

[12.5] Samsung Spinpoint F1 1TB for $79.99

[10.0] WD20EADS $199.99 @ Dell Home

....and I could readily see that the Samsung 1TB drive is a better deal/value/bang-for-your-buck as compared to the WD 2TB drive.

 

I perform this simple calculation anytime I'm evaluating a hard drive on sale.  It is not the only thing I look at, but it gives me a quick way to determine if today's OMG CRAZY BLOWOUT sale is worth looking into or if its just hot air.  My rule of thumb when deciding when to buy a new drive (assuming I have the luxury of waiting out the sales) is to compare this ratio with the last time I bought a drive.  So, the last drive I bought was a WD Green 1TB for $90 = 11.1 GB/$, whereas the drive I bought today gave me 12.5 GB/$.  Clearly an improvement.

 

Anticipating a bit of criticism, I will say that clearly this ratio is not the only thing to consider when purchasing a new drive.  Other parameters, especially the rotational speed and cache, are important to compare and contrast when comparing different drives.  Of course you will also want to pay attention to reviews, recent changes in firmware, and other factors that may add or decrease value to certain drives (a $70 1 TB Hitachi drive that dies after 3 months is not a better deal than a $100 1 TB WD drive that lasts for years).  Still, since the particular application of unRAID is very tolerant to mixed drives and generally isn't geared towards performance (I mean, if you are buying a new data drive, are you going to notice the difference between a 16 mb and a 32 mb cache?  probably not), then it seems to me to be an appropriate measure.

 

Feedback encouraged.  Have at it.

I've seen it computed the other way - $/gig and not gig/$.  (e.g., an $80, 1T drive is 8 cents per gig, vs a $200, 2T drive is 10 cents per gig).  Same idea though.  It's just a little more intuitive that lower (cost) is best.

 

Used to be common to see that stat posted, when drive sizes were somewhat closer together (400GB, 500GB, 640GB, 750GB, and 1T).  But now the choices are farther apart - 1T, 1.5T, and now 2T.  I think people make purchasing decisions more based on ...

 

1 - Brand / brand features (e.g, GP drives for lower power and low heat vs 7200 RPM slightly faster drives)

2 - Ultimate array size (buying 1T drives limites you to a 15T (soon 19T) array, whereas 2T drives double that and halve the power requirements

3 - Size of current parity drive - if someone already has 14 1T drives and wants to add more space, they may just want to stick with the 1T drives rather than having to buy 2 of the bigger drives to get any advantage.

 

I think people tend to know what brand(s) and size they want, and are waiting for there to be a good deal on that to pull the trigger.  Rather than looking at just the price.  Not to say that $10 1T drives wouldn't create a buying frenzy, even if they were not your normal brand, but for the normal deals I think this is true.

I used to purchase cheapest per GB but after a point heat became so much more important to me than per GB cost. This basically limited my choice down to WD Green for the longest while.

 

Theres also the global nature of the community. Converted to dollars I would pay way more than you guys for drives.

 

I think it is a good idea though but done via a forum discussion like this one and a wiki backend.

 

i.e. someone finds a deal posts it here and tweaks a  simple wiki page. this way we can keep trak of changes over time as well