W520: go for Raid 0? How much will battery life suffer? Vertex 3 VS Crucial C300

I have a W520 incoming, and I'm considering harddrive options. Right now I'm leaning towards getting two 128GB Crucial C300's, garbage collection will work as long as there is ample space left on the drives, but I'm a bit worried about power consumption.

Here are scores from AS SSD, which uses incompressible data, relevant for photoshop user, in video editing etc which I'll be doing. The compressible results from e.g. ATTO should favor the OCZ drives, but incompressible seems more relevant for most workstation use, along with random 4k reads, which the C300s are great at.

2xCrucial C300 = $400 for 256GB (should get more points on the W520)


2xVertex 3 120GB = $600


1xVertex 3 240GB = $550


If battery life isn't too horrible, C300 in raid 0 seems like the way to go!

 

bumpitybump

 

I would probably advise not to do RAID 0 with the C300. The idle garbage collection on it is apparently rather lackluster. Without TRIM support you'll be looking at some pretty bad performance degradation.

The SSD Diaries: Crucial's RealSSD C300 - AnandTech :: Your Source for Hardware Analysis and News

I personally would just recommend a single Vertex 3 240GB as their performance is markedly better than the 120GB version (again, check the Anandtech review for it). Due to certain amounts of overhead introduced with RAID0, I've heard that boot times are in fact even longer (initializing the RAID array?) and it can even be slower during normal use as well on certain occasions.

However if you're dead set on RAID 0, Vertex 3 would be the way to go with the significantly improved garbage collection. I don't really have too much experience with battery life with RAID 0, but I can't imagine it'll be a huge hit, but I don't exactly picture a W520 as really a "portable" machine either.

 

Anandtech also says that this was fixed in firmware rev 0002. Currently drives ship with rev 0006. So I think thats not an issue any more.

But +1 for one large SSD instead of RAID-ing two small ones. The flash controller essentially implements a RAID-0 over the flash chips, and actually knows the storage layout. And you free up one HDD bay for storage.

 

I would not do RAID0 on any OCZs right now.
Actually, I would probably not do it on anything but Intel, and then again I would probably not do it at all. But that's just me.

 

One vertex 3 240GB is significantly more expensive than two C300s, and significantly less fast, especially for in-compressible data. People have run C300s in Raid 0 before and have found ways to deal with the lack of TRIM - doesn't seem to be a real issue, its garbage collection seems pretty good actually.

So, the main thing is battery life hit and/or stability issues. Cause it doesn't make no sense to spend a lot more money on something a lot less fast now does it?

240GB vertex 3


256GB C300 Raid 0

 

The initial question appears to be about possible differences in power consumption between having 2x120/128GB Vertex3 or Crucial C300, in comparison to having 1X256GB Vertex3 or Crucial C300. Obviously, having 2XSSD running will use twice as much power as 1XSSD, and that will affect battery life - but significantly? According to the manufacturer's specs, 2X128GB Vertex3 will use 2X1.65w in idle, and 2X3w active; 2X128GB Crucial C300 will use 2X0.85w in idle, and 2X1.5w active. i.e. a total of 2.3w idle and 6w active for 2XVertex3, and 1.7w idle and 3w active for 2XCrucial C300. Considering the cpu is rated 35w/45w, and dedicated gpu 45w/55w, only if the internal gpu is being used and the cpu powered down would saving a little power with the SSD choices be of much significance. Choosing the 2XCrucial over choosing the 2XVertex3 will save 3w (active); choosing 1XCrucial over 2XCrucial will save 1.5w (active), and choosing 1XVertex3 over 2XVertex3 will save 3w (active).

 

Although I'm not positive about the newer SSDs, I believe SSDs either draw 100% or sit at idle. There is no in between. Having a RAID config will cause both your SSDs to run simultaneously so going RAID should double the amount of power it takes to power your SSDs compared to having only one SSD.

According to Anandtech, the Vertex 3 6gbps will draw 4.46 watts when not idle. Unless your SDDs will be running consistently, I agree with antskip and don't think that going RAID will affect your battery life tremendously.

The OCZ Vertex 3 Review (120GB) - AnandTech :: Your Source for Hardware Analysis and News

I've also read that switching from Optimus to discrete GPU only will effectively take your battery life on a full charge from 6+ hours down to around 3 hrs. For simplicity, assuming that going RAID causes an additional 4w of power (10% of the increase from switching to discrete GPU only), I would expect RAID causing a maximum reduction of 18 minutes during heavy SSD usage. I know the math is suspect but I don't think you need to worry about the additional power draw from using RAID.

 

Running two SSDs won't necessarily lead to twice as much power being consumed, as they'll be more efficient and do transfers ~70% faster - so they could be idling up to 70% more

But I'm sure some inefficiency might lead to an extra powerdrain in raid 0. Only one way to find out (although I'd assume it's more like 4 than 2w..)

 

Ok, did some thinking.

The W520 had a 94 Wh battery, and can give you 10 hours, i.e. consuming 9.4w when idle.

If you up that idle number by 1W, you cut battery life with 1h, by 2W, 2h etc. But it seems that the drive wouldn't use more than 0.5w when idle. phew

 

Agreed...I think you are in the clear. If you have battery life issues, it won't be from the RAID.

 

On that note, the crucial M4 has a very low idle power cosumption, 0.15W, slightly slower reads, 4k and seq, but faster writes than the c300.