W520 & RAID option - some questions

[Alejandro Audisio]

I think I understand what the RAID option on a Thinkpad is, but I want to double check my understanding with the experts here.

If I select this option, will I get a small SSD that will work together with my conventional HDD...? If this is the case, what is the size of thie SSD and does the SSD become the boot drive by default...? What happens to the logical drive designations... is the primary HDD still the conventional driver under the letter C:> or does this work another way...?

Also, it seems that if I select the RAID option, I cannot at the same time get the CD/DVD disk drive on the system.... why is this....? Is this a "real estate" limitation because the RAID means that Lenovo needs to use the space of the DVD drive for additional electronics...?

Furthermore, if I go with RAID, will Lenovo sell me an external DVD reader/writer so I can still use normal disc media....? I assume that an external drive of this kind will be USB, correct...?

Final question... for a laptop that has no DVD drive, what sort of media do you use for recovery actions....?

I appreciate the patience of all with my dumb questions !!!

[libussa]

Okay, let's take a few steps back

RAID means redundant array of independent disks, the key word here being redundant.

Basically, you need at least 2 drives to do RAID. You have different types of RAID : RAID 0 to RAID 6 are the standard ones. For your case, with a W520, you are limited to 2 drives, so you can only do RAID 0 and RAID 1. (RAID 2-5 needs minimum 3 drives, RAID 6 4 drives).
In each case, Windows will see your drive as one logical drive (c:\, like you said). So, like a logical drive, you can partition it, or do whatever you want.

So let's take a look at RAID 0 and 1 which are the 2 modes you'll have to choose from. Let's say you have two 500 GB drives in your machine.

- RAID 0 : You put your 2 drives together to make a 1000 GB (1TB) logical drive.
++ Pros : increased reading & writing speed
-- Cons : no fault tolerance : one drive fails, ALL your data is at risk

- RAID 1 : Your 2 drives are mirrored : one is the exact copy of the other. You have a 500 GB logical drive
++ Pros : increased reading speed, fault tolerance (if one drive fails, your data is safe (up to a point))
-- Cons : standard writing speed, two drives for half the storage space (price of security...)


So, now for the hardware part. Theoretically, you could do RAID with different drives, but that's a waste because you would be limited by the smaller drive ; so you need 2 identical 2.5 inches drives. That's why you can't have an optical drive (DVD) : the second 2.5 inch drive goes in its place, in a caddy. You'll much likely use mechanical drive, or if you have money to spend, 2 SSDs (incredible performances then).

So you can buy an external USB DVD writer if you need it. I don't know if Lenovo sells one, but my guess is it would be cheaper anywhere else...
Or, for recovery / installation purposes, you can use a USB key, which is a lot faster...

The third storage option on the W520 is mSATA, which allows you to plug a small SSD drive in place of a WWAN adapter. Today, they are of smaller capacity, slower and more expensive compared to 2.5 inch SSD, but it can be a good alternative for a boot drive if you want to keep your optical drive, or if you want to do RAID

Finally, all the configuration, like which drive to boot on, or whether to use RAID 1, RAID 0, or no RAID at all, is easily modifiable afterwards. BUT you have to order RAID on your config if you're planning on using it, you can't activate it afterwards.

[Q-Ball]

Alright, so a couple things:

If you get an SSD it's going to be far faster than any HDD RAID 0 array could ever dream of.
RAID 1 is nice to have, but is it possible to do an external backup?
There is an eSATA port on the machine that you can use for a backup drive, after all.

You can't have hardware RAID on a machine not pre-configured; they leave off a specific part (for some reason).
You can do it through software but your performance will suffer; also, I've never heard of a solution like that working on Windows. Linux can do it though but that's far from an ideal solution.

You can order the DVD drive from Lenovo; the bay the DVD drive sits in is not fixed so you can swap things in and out as you please (which is what it's designed for in the first place). You can do the same with the 2.5"-to-UltraBay adapter but you won't have RAID capability if you order it not pre-configured.

Of course, you'll then have another hard drive sitting around.
Getting a 2.5" enclosure that can run on either eSATA or USB 3.0 would be a wise choice if you have no other machines to use it with.



How much space do you need on this machine, anyways? Is 240 GB enough, or do you need more? There are good 120GB mSATA drives out there (they'll run you about 200 dollars), and 240GB SSDs are about 300 dollars (Chronos Deluxe, NCIX US, also there are some a bit cheaper there as well).

If I were you, I'd just buy as large an SSD as I could afford and put the hard drive where it needs to be if you need more than 240GB of space.
You can RAID SSDs as well, so if you think you'll ever need that functionality you'll have it (i.e. another 240GB of space) but that shouldn't really be an issue.

[http302]

This is my experience with regards to RAID.

RAID has to be live all the time or else it will fail. You can't make a RAID 1 array with an internal drive and an external eSATA port and expect it to work well when the eSATA drive is removed.

Plus, Lenovo's onboard RAID solution only works between the HDD and ODD ports, not with the eSATA or mSATA ports. *AND* if you did not select the RAID option at ordering, you cannot use hardware RAID on this system, period.

Food for thought...

[libussa]

I guess except for very specific use, you'll be better off with SSD (SATA or mSATA), plus another disk (large SSD if you have means, big fast mechanical else).
I f you need large amounts or storage, or you want to do secure backups, you should go with a NAS with an array of disks in RAID.

[Kaze22]

The only benefit of RAID is you can get cheap 1TB of RAID 0 giving you about 160mb read and write.
If you try to run SSD RAID, you'll run into the problem of TRIM support.
Win 7 won't do TRIM on RAID.
So you'll start off at 800mb read/write and quickly drop down to half of that in a few months of use.
Kind pointless if you ask me.
I'd just save some money and get a bigger SSD and keep the Optical Drive.

[QFoam]

If you try to run SSD RAID, you'll run into the problem of TRIM support.
Win 7 won't do TRIM on RAID.
So you'll start off at 800mb read/write and quickly drop down to half of that in a few months of use.
Kind pointless if you ask me.

Kaze22, that's an interesting point. Here's some updated info:

Intel to Finally Provide TRIM Support in RAID0
http://www.tomshardware.com/news/Intel- ... 14048.html

SSD Raid 0, no trim? big deal?
http://www.techpowerup.com/forums/showt ... p?t=162502

Intel SSD 520 RAID Review
http://www.storagereview.com/intel_ssd_520_raid_review


Dual SSDs in RAID0 will be on my next 17" laptop, probably a Sager w/dual fans, multiple hard drive bays plus optical bay/drive, NVidia's fastest non-SLI GPU setup, and built-in 3D display. I use a Synology NAS over my local network for mass storage and backups (currently contains three 3TB drives in RAID5, with room for two more), transferring files to the laptop's drives for processing (mainly image files, ranging from tens to hundreds of megapixels). For more info about the NAS, click here.

[Kaze22]

If it'll only work on Intel ssds then its not something to write home about.
Some drives do have hardware garbage collection, but not all ssds.
As for no trim no big deal, I can attest that trim is vital.
My X301 has an older ssd with no trim.
It went from 160mb r/w to 90mb r, 20mb w, in less then 6 months of use.
I have to run Tony Trim, or secure erase on it every 6 months.
It ain't fun.

If you write to the drive oftern its OK, but if you plan on writing to the drive often no trim will kill performance in no time.

[QFoam]

If it'll only work on Intel ssds then its not something to write home about.

The TRIM support is being added to the Intel Rapid Storage Technology driver, so it's being added to the storage controller that's built into the computer, and isn't for a specific brand of drives. So TRIM should then work for RAIDs built from drives of various manufacturers, although who knows whether wrinkles will be experienced by some manufacturers.

For anyone who's interested, here are some additional details on TRIM support and RAID, from the SSD section of Intel's support community (the posts from user "parsec" are particularly informative):

http://communities.intel.com/thread/179 ... 0&tstart=0

Anyway, thanks for bringing all of this up, Kaze22. It's an interesting issue.