EggXpert

These are benchmark results of a pair of 300GB WD VelociRaptors running on an SB700 RAID-0 setup vs. a RAID-5 of four 7200 RPM hard drives on a 3ware 9650SE RAID card.

Here is the benchmark from the 300GB WD VelociRaptors running in RAID-0 with 128KB stripe on an SB700 onboard chipset ( ASUS M3A78-CM ). I would have liked to use a larger stripe to improve random access performance, but these cheap onboard chipsets don't give you much options.

You see that squiggly line? That is a problem..  Really, the I/O should not be performing like that at all.  As the head gets closer to the center of the drive, the performance of the drive should drop accordingly, I believe the irregular squiggly line indicates that I'm having issues with the SB700 chipset / controller keeping up with these drives in RAID-0.  I'm running 64-bit Windows Vista with latest drivers, latest BIOS, latest patches, and I've tried it with native command queuing on and off.. I get the same results everytime..  The image above clearly shows that there is a problem in the I/O system that is not related to the hard drives themselves.   Also note the CPU usage in the graph, a little high at 12.5%, this is an AMD 5050e Dual-Core 2.6 Ghz.  Vista seems to do a great job at balancing the CPU across both cores and so this 12.5% is in fact a 12.5% load on two cores simultaneously.  Despite the CPU load, there is still something either in the I/O controller, in the drivers, or in the chipset that is preventing these drives from running to maximum capability..  Theoretically, each of these drives should be hitting 160MB/sec which means I should be at least 320MB/sec... (Edit: 10/8/09 See Correction below) If you take the tail end of the curve and arch the front part of the curve upwards to account for the performance difference due to the radial data storage location of the data, you can see where it "should" be.  It's only on the very end of the graph ( inner spindle) of the drives where the chipset/drivers/rest of the IO system starts to catch up to the hard drives.  Data access on the inner circles of a hard drive platter of course are slower since the platter always spins at the same speed and of course due to the smaller diameter of the circle, less data is traveling under the head per revolution.  That's why it's only in the very end of the chart where the drives just almost start to become the bottleneck in the I/O system.  In this setup, I could estimate I'm losing at least 80MB/sec due to a lack of controller performance on the motherboard.

Correction: The HD Tune stats of a single 300GB Velociraptor are below...
Transfer Rate Minimum : 72.7 MB/sec
Transfer Rate Maximum : 118.4 MB/sec
Transfer Rate Average : 99.4 MB/sec
Access Time : 7.3 ms
Burst Rate : 158.5 MB/sec
CPU Usage : 2.3% 

More transfer stats on these raptors are reviewed here:

http://www.uberclocker.com/?page_id=95

 So I'm getting only about 60% speed-up when putting two of these drives in RAID-0, mostly due to chipset / driver limitations on the SB700.

Now let's take a look at a RAID-5 setup with four hard drives.  3 of the drives are Seagate and the fourth drive is a WD..  Yes, I know it's VERY bad to be mixing drives in a RAID array, but in this situation, I just couldn't get my hands on another old Seagate drive and even if I could, I couldn't stomach paying a premium for it when newer drives give you so much more capacity for your money.   Below is from the RAID Controller's configuration page which is an HTML document that you interact with in a web browser, just like setting up a router..

Again, yes I'm well aware that WDC drive in the RAID array is an ugly duckling and most of the capacity of the WD drive is going to be lost while it's in the RAID-5 array.  The WD drive of course, will shrink down to 149.05GB size of the other drives..  However, as it turns out, this is much less of a problem than you would expect.. In fact, I didn't have any issues at all with the WD drive in the array.  No issues deploying the RAID and certainly, as you will see below, no issues with RAID-5 performance.

 Four Desktop grade 7200 RPM drives running in RAID-5 on a 3Ware card with 256KB stripes.

 And there we have the beautiful curve that we would expect to see when the hard drives themselves are the bottleneck in the I/O system.   Also a thing to pay attention to is the CPU usage.  It's only at 3.4%, this is an old AMD Athlon 64 (single core) 2.1 Ghz CPU and it's only using 3.4% of a single CPU core to hit much higher transfer speeds than the setup above.

Thanks for reading! Remember people, Raid-5 is not for onboard chipsets... I saw massive performance drops switching from a 3 drive RAID-0 array to a 4 drive RAID-5 array back when I was using the onboard RAID controller. I threw in this 3ware controller and I'm now seeing performance exactly where it should be when the performance of the drives themselves is the bottleneck.  These are not low performance drives either, they had the biggest cache, fastest RPMs, best warranty, and best access times of just about any Desktop level (Raptors I consider to be Workstation level) hard drives out there.

Conclusions that I've made thus far:

• The SB700 chipset, and most likely other onboard RAID chipsets are insufficient for a RAID-0 setup using Velocirapters if you wish to get all the performance out of your raptors.
• RAID-5 should not be used with any onboard chipsets if it's at all possible to avoid.  I saw a massive write performance drop moving from three drive RAID-0 to a four drive RAID-5 on an nvidia 570 Ultra chipset.
• RAID-5 should have a write-back cache to significantly boost performance. I'm seeing over 500% performance boost on random writes with write-back cache enabled on a RAID-5 array. 
  
• During a sudden power loss, having a large write back cache will likely mean more lost data and more corruption.  To counter this, make sure you either have an UPS unit or a battery backup module for your RAID Card.  Personally, I recommend an UPS unit since the battery backup modules for RAID cards are quite costly and are often make/model specific to the RAID card.

Coming Soon:

Raptors with a Raid Card! I just need to decide which RAID card to go with as my other RAID card doesn't have any more spare ports.

I've been using Netflix for 2 years and I love it.  I've rented well over 200 movies so far and although I've had a few of them come scratched & unplayable, I must say that Netflix's service can't be beat..  I've tried Blockbuster and it takes them about 3-4 business days to ship me a DVD and with Netflix, it's always in the mailbox the day after they ship it..   Netflix has a massive Anime DVDs section and they also have some Anime On-Demand (Watch it live over the Internet).

I just got a link from Netflix that I can give out which will give you a one month Netflix free trial instead of the regular 2 weeks..

Good for: 1 month of Netflix DVD Rentals EXPIRES: 9/30/2007 (Quantities are limited.)

http://www.netflix.com/Default?mqso=80015523&nfso=64972086

Restrictions:
1) EggXperts Only! Do not share please!  I only have 5 vouchers, when they're gone, they're gone...
2) Only those who have never signed up for Netflix are eligible for a 1 month free trial.

Getting Recently Released DVDs FAST!

I'd just like to point out, that I just rented the DOA:Dead or Alive DVD, and I was able to get it the day after the DVD's release.. Netflix shipped on the day it released, you just can't beat that..

Scratched or Damaged DVDs?

On a few ocassions, Netflix has sent me a rented DVD that was so badly scratched it was unplayable.. Keep in mind, that I've rented well over 200 DVDs, and about 5 or 6 were unplayable..   So I simply filled out an online form, mailed the DVD back, and Netflix sent me a replacement.. Easy as pie, but I must admit it is a little annoying.  I wish DVDs didn't scratch as easily as they do! 

Edit:   Also, it's interesting to note that it seems my computers are much more picky about scratched DVDs that the full size DVD player hooked up to the television.  I'm not certain exactly why this is, but the DVD drives in computers tend to get stuck when there is a nasty scratch on the disc for several minutes while the regular DVD players often just skip over that part and keep on playing immediately.. I really wish computer DVD players were a lot better.  Maybe it's just my $20 Lite-ON drives giving me the headaches with the DVD playback on moderately scratched discs or maybe there is something more, honestly I have no idea..  Usually I just send a DVD back to Netflix if it doesn't play on my computers, but as noted, I've found that sometimes it will play on the Television DVD Player when it won't on the computers.

Prices, Costs, and What You Get 

If you pay $5 a month for renting DVDs from Netflix, then you get 5 hours of Netflix On Demand in addition to the rental, so that's quite a deal..  If you pay $17 then you get 17 hours in addition to your 3 at-a-time rentals (when you ship them back, they ship you the next movie in your queue).. The largest number of movies I've been able to rent in a month with the 3 at-a-time plan was 20, but you need to send them back the next day you get them to rent that many a month.. Of course it also depends on how close you are to a Netflix shipping facility, and that's what the free trial is for .. Use the free trial for testing out the turnaround which is generally quite remarkable..

Note: Purchasing rented/used DVDs is not such a bad idea!

One of the things that Netflix members have access to is the ability to purchase some of the DVDs that Netflix rents out at a massive discount.  This is something that many people overlook and one of the less interesting "perks" of being a Netflix subscriber.. Buying shelf priced $29.99 DVDs a couple weeks after the DVD is released for $8 is something that you just can't pass up.. It's an undeniable bargain! 

I've bought a couple of used DVDs from Netflix for about $5 each and they came in their original case (case was in perfect condition) with light scratches on the DVD, but the DVDs were 100% playable. Now I haven't purchased enough DVDs from Netflix to know whether or not it's possible to get an unplayable DVD, Netflix guarantees DVD purchases to be playable, so you can get a replacement.

Unfortunately, not all DVDs that Netflix has are up for purchase! Netflix decides which DVDs they're going to sell, which is a little bit of a disappointment.   I want to be able to buy all my DVDs from Netflix, but often that option is not available for most movies that Netflix rents out.

Q: Movies on Demand, It can't be that good can it?

Actually, it's good... Very VERY good.. In fact, it totally blows other services such as Joost out of the water. ( If you need a Joost invite, send me a PM with your e-mail in it).   If you've ever used Joost, you know that it suffers from two major show-stopping problems.. The first being that Joost has poor quality video (at least compared to Netflix On Demand) and also Joost is very resource intensive. I am unable to run Joost on my 1.2 Ghz Celeron where I can run Netflix on Demand quite well at full-screen..
    But why is low system requirements important for Netflix On Demand?

It's very important because it allows you to build a cheaper and cooler running HTPC! You don't need to cram as much horsepower into your HTPC if you're going to build a computer solely for the purpose of watching Netflix On Demand as compared to Joost..   I have been fiddling with the idea of building a tiny HTPC and using it almost exclusively for Netflix, and anything above a 1.2 Ghz Celeron would be sufficient.

For those of us who already have Netflix, we love our Netflix On Demand, and it's getting better everyday! Most recently, they added the entire Xena series (all seasons) and I can watch an episode whenever I feel like it without having to wait 24-48 hours for the DVD to arrive. Keep in mind, that the On Demand service is in addition to your regular renting service. It's a perk that you can choose to use or not and you get it free of charge without having to pay any more for your Netflix subscription!

Conclusion: Blockbuster has NOTHING that can compete with Netflix On Demand.

Q: Does Netflix Throttle DVDs?

I don't know where this came from, but in my 2 years of using Netflix, I have found absolutely no evidence for this at all!  As I've said before, I've been quite capable of renting up to 20 DVDs a month AND watching 17 hours of Netflix On Demand while using the $17 a month plan..  And I never had any problems at all.     The only time I ever see DVDs on "Short Wait" is when they are first released on DVDs or on other rare occasions (described in paragraph below). As an example, the DOA: Dead Or Alive DVD was on "short wait" the day it was released. However, as I noted above, the DVD was in my mailbox the next day anyway! Which was quite a pleasant surprise for me.

There have been a couple times where I've had a "short wait" for an unpopular movie or anime.  I've even had it crop up right in the middle of an Anime series that I was renting, and Netflix jumped over the anime series and sent me a movie in my queue instead.   But does this mean Netflix is "throttling" me?

Highly doubtful, because there's just no evidence of it..  Most likely these "short waits" are caused by Netflix having a limited number of DVDs for a series and a few people returning DVDs that they scratched up so bad they can't be rented out to anybody else.. I have my own evidence that shows Netflix does NOT throttle and the short waits appear equally to everybody.. When I reported a DVD I had received a few months ago that was unplayable, the movie showed "Short wait" while Netflix shipped me a replacement.. I asked a friend who also had a Netflix account and my friend confirmed that the "short wait" showed for them too! So it wasn't Netflix throttling me, rather it was just an unexpected demand or caused by a recent report of an unplayable DVD.  Again, my own evidence shows, Netflix does not throttle..   I'm hoping that MythBusters will have a look into it and make a whole episode out of it!  As a 2 year subscriber to Netflix, there were some months that I rented as many as 20 DVDs on a $17 plan without thinking much of it..

Conclusion: I can say with strong confidence that Netflix Throttling is a MYTH.
 

Edit: However, there are those who will disagree with me and have collected their own evidence saying that Netflix throttling is very real. (Use google)..

I just haven't experience it myself at all..  I guess I'm just lucky? 

Anyway, here's an interesting chart for the month of August, 2007..

Source: http://www.manuelsweb.com/netflixjournal11.htm

Ask a question about Netflix, and I will answer it and add it above! 

Edit: Don't forget, NewEgg sells DVDs too! Although NewEgg's selection is not quite on par with Amazon, I have found quite a few hard-to-find foreign DVDs on NewEgg's site for even better prices than Amazon! So make sure you check the price and availability on NewEgg before buying your DVDs somewhere else! You might be surprised!