Sure it has been done before, but I just wrote this up as an email response and figured I would share:

 

Norco 4220 vs Norco 4224.

 

The nice thing about these cases is that all the hardware that works in one will also work in another.  For example, consider this hardware:

 

20 Drive Budget Beast

 

The above link lists all the cables and other hardware you'll need for the cheapest possible 4220 build.  To create the cheapest possible 4224 build, you will need all of the same hardware plus an extra reverse breakout cable (so a total of two of those cables).  This second reverse breakout cable would hook up to the 6th backplane, and two of its four SATA plugs would connect to the last two SATA ports on the motherboard (the other two SATA ports would be unused, as would the last two drive bays in the case).

 

That's all you need to max out the 4224.  If at some point in the future unRAID ever supports 24 or more drives (which I consider to be likely, but I have no idea when this will happen), then you could always add a cheap 2 port card to the motherboard's PCIe x1 slot and claim those last two drive bays.  No extra cables would be needed, since you would already have the two unused SATA plugs on the second reverse breakout cable.

 

The base price for the 20 Drive Budget Beast at today's prices is $900.  Add the extra cable and higher price of the case you need for a 22 Drive Budget Beast and you get a total of about $985.  These prices are without drives or shipping or the unRAID license.  So let's break it down per drive bay:

 

With the 4220, you get 20 drive bays at around $45 each.

 

With the 4224, you get 22 drive bays at around $44.77 each.

 

So it comes out to be basically equal.  That's good news, because it means you can justify the 4224 more easily (even with the two 'wasted' slots).

 

Now let's look at the capacity of each server.  Both the cache and parity drives are completely optional.  You can have up to 20 data drives if you wish.  However, if you choose not to use a parity drive, you won't have any protection from drive failure, so most people prefer to use one.  The cache drive only helps with write speeds, so for the common media server application of write once read many you won't need a cache drive at all.  So that means that with the 4220 you could have one parity drive and 19 data drives (38 TB of space) and with the 4224 you could have one parity drive and 20 data drives (40 TB of space).  If that isn't enough space for you, you'll have to build multiple servers. To break it down again, let's assume that you filled each server to the brim with 2 TB drives each of which costs $100:

 

With the 4220, you get 38 TB for $2900, so about $76 per TB of storage.

 

With the 4224, you get 40 TB for $3085, so about $77 per TB of storage.

 

Again, basically equal.  If you can afford the 4224, it seems like a better deal overall at today's prices.

Max 20 data drives until Tom changes it. Use of a cache drive doesn't change things.

Max 20 data drives until Tom changes it. Use of a cache drive doesn't change things.

 

Yeah, I'm hoping for 2 extra data drives so we can fill the 4224's to capacity. Only 2 slots left until mine is maxed out with the current drive limits.  

I had a feeling I got that wrong.  Thanks for the correction.

 

The official unRAID page is misleading, as it says '20 array drives'.  The parity drive is most certainly an array drive, so that means one parity plus 19 data plus one optional cache.

 

Anyway, I fixed the original post and reworked the math.

I had a feeling I got that wrong.  Thanks for the correction.

 

The official unRAID page is misleading, as it says '20 array drives'.  The parity drive is most certainly an array drive, so that means one parity plus 19 data plus one optional cache.

 

Anyway, I fixed the original post and reworked the math.

 

I think you were right the first time? You can have: 1 Parity and 20 Data drives. The 4224 could max out at 1 Parity and 23 Data drives. 4220 does max out at 1 Parity and 19 Data drives.

I had a feeling I got that wrong.  Thanks for the correction.

 

The official unRAID page is misleading, as it says '20 array drives'.  The parity drive is most certainly an array drive, so that means one parity plus 19 data plus one optional cache.

 

Anyway, I fixed the original post and reworked the math.

I think you might need to fix it once more.

 

From the source files:

/* The maximum number of disks per array that we support. */
#define MD_SB_DISKS                     21

20 data disks, plus parity, plus an optional cache drive.  22 physical disks total.

 

The official manual page is out of date.

 

C'MON MAN!

 

lol....jk Raj...

Plus with the 4224 you can get the new fan plate, not have to hack it up, and make your 4224 a WHOLE lot quieter

Thanks for this post Rajahal

 

Next year I want to buy a Norco 4220 or 4224.

 

I suposse you can not use a SSD with the Norco 4224.

You could if you mounted it inside the case with velcro. 

You could also use an SSD or other 2.5" drive with one of these drive converters.

 

I agree, the new official fan plate is another big plus for the 4224.

 

I believe what is currently written in the first post is correct:

 

The 4220 maxes out at 19 data drives and 1 parity drive, or 18 data drives, 1 parity drive, and 1 cache drive.  20 physical drives.

 

The 4224 maxes out at 20 data drives and 1 parity drive, or 20 data drives, 1 parity drive, and 1 cache drive.  22 physical drives.

 

Another thought about the 4224 - those last two drive bays could be used as dedicated preclear slots, or to mount more unprotected drives using SNAP (sort of like extra cache drives, but not linked to the array like the official cache drive).  Finally, perhaps they could be used for RAID 0 or RAID 1 and accessed for certain tasks, sort of a server-within-a-server kind of thing.

You could also use an SSD or other 2.5" drive with one of these drive converters.

 

Didn't now this exists. Good idea! Now you can use a SSD as cache drive. So i have to buy a 4224... 

 

Thanks Rajahal.