Precision M6400 Owner's Lounge

Sorry, I have to fix this disk & raid discussion... It seems to be a confusing topic and I blame uneducated hard drive reviewers on sites like Tom's HW.

1: People are passing around maximum sequential transfer rates as if they're the typical performance expectation. You only get that when reading or writing one large file at a time, on a perfectly defragged volume, with no other disk activity present. That almost never happens. (Where is that data going to or coming from?) Your typical transfer performance will be random read/write, 7 to 12 MB/sec for a single 7200rpm drive at pure random, and probably hovering around 20-30 MB/sec for typical workstation-style usage which will be a combination of random and sequential access. This is because your computer is usually using data from more than one file at once, or reading and writing at the same time, or maybe just isn't 100% defragged.

2: SSD drives have a huge advantage because they do not suffer from this. So to compare 2-drive raid-0 of 7200rpm disks (typical maybe 30-50MB/sec) you will always get better performance with a single SSD.

3: SSD drives do not last forever despite the popular assumption... Yes they have no moving parts, but they also have limited write cycles similar to flash drives. They DO work out, for good ones (big quality differences out there for these), to last longer than your typical rotating drive by a decent margin. But it's not enormous.

4: I've had bad experiences with raid-0 as a primary OS drive. My card would drop the array suddenly if a drive encountered a bad sector, and that would crash windows instantly with no event logs. (not even a bad sector event - the OS couldn't write one because the drive was gone!) I'm not necessarily saying that's what would happen on the hardware in the laptop, I don't know for sure. It will be an interaction between the way the drive responds to bad sectors, the way the controller responds, and the controller's timeout period (can drop due to either drive timeout OR programmed response to bad sectors.) I would personally get large 7200rpm drives and use Raid-1, because the risk of drive failure goes way up in laptops, and that way I'd never have to worry.

My recommendation for people with money would be an SSD primary drive with applications and OS, and a spinning platter secondary drive for large storage. Since that drive would hold mostly data, you can easily get away with 5400rpm and get 500 gigs on that baby. I personally have had difficulty actually identifying a difference between MEASURED power consumption of 5400 vs 7200 rpm drives. It seems to be divided up by manufacturer far more than by rpm. So I would buy a 7200rpm drive since I deal with very large projects containing streaming data. (Which is pretty unique to visual effects... 90% of people won't have that need.)

 

Sorry I got sidetracked talking about storage... I'm a big Raid enthusiast.

(BTW, Raid 0 is definitely classified as Raid, it's just not redundant unless combined with other levels. i.e. Raid-10, Raid-01, Raid-50)


What I'm wondering is, have people been able to GET their Precision M6400s? Did it take a really long time? I waited on one for over a month before I figured it was a lost cause. (ordered 9/26, gave up and canceled last week 11/5!)

I put another order in for a Covet since the first was waiting on the screen and the Covet uses a different model. But I'm in a situation where I must have a laptop within the next month and a half, or I will have problems. (I've been trying to get a stable laptop since 7/20!!! HP failed utterly so I'm looking at Dell. At least HP could ship?)

 

Not to the point that I'd worry about it. I suppose theoretically they might be just because they spin faster, but that would be easily offset by 100 other things.

Not really, but you double your chances of losing your data by using RAID 0. I hate RAID 0 even on a desktop, and on a notebook, where it might accidentally be dropped, or whatever-doubling your chances of failure just sounds terrible to me.

Too bad RAID 1 isn't more common. It has some speed boost too (if it's done right at least)...

 

Thanks for the input. The problem is that 64GB is not big enough even just for apps.

CS4 Master Collection alone is: "24.3GB of available hard-disk space for installation; additional free space required during installation (cannot install on flash-based storage devices)".

 

Sure it's classified as RAID, but by definition it's not

 

I think they may be referring to removable flash devices like CF Cards, etc. I guess I'll find out when my laptop arrives.

 

Much appreciated. Very positive review.

 

"4: I've had bad experiences with raid-0 as a primary OS drive. My card would drop the array suddenly if a drive encountered a bad sector, and that would crash windows instantly with no event logs. (not even a bad sector event - the OS couldn't write one because the drive was gone!) I'm not necessarily saying that's what would happen on the hardware in the laptop, I don't know for sure. It will be an interaction between the way the drive responds to bad sectors, the way the controller responds, and the controller's timeout period (can drop due to either drive timeout OR programmed response to bad sectors.) I would personally get large 7200rpm drives and use Raid-1, because the risk of drive failure goes way up in laptops, and that way I'd never have to worry.

My recommendation for people with money would be an SSD primary drive with applications and OS, and a spinning platter secondary drive for large storage. Since that drive would hold mostly data, you can easily get away with 5400rpm and get 500 gigs on that baby. I personally have had difficulty actually identifying a difference between MEASURED power consumption of 5400 vs 7200 rpm drives. It seems to be divided up by manufacturer far more than by rpm. So I would buy a 7200rpm drive since I deal with very large projects containing streaming data. "

Thanks for the input.

Raid-0 as a primary OS drive looks like a big no-no.

Looks like I need to rethink safety vs speed vs cost vs what is available from DELL (entire system has to be configured by them).

 

Config I put together last night said ship date 11/30.

 

What was your Covet config? I wonder what is different on mine that has added weeks to the ship date...