SCSI performance effects practically everything you do on your Mac. From loading apps to saving files, the speed of your disk system makes a world of difference. Over the past three months I've researching the pros and cons of putting together a RAID for my Mac. I've wanted to do this for a while, however the price and trouble involved has held me back. Finally about three weeks ago I bit the bullet and decided to put something together. The costs involved in moving over to Ultra-Wide can be expensive. For best performance, I would only want to connect UW devices to my UW bus. There really is no sense in connecting slow SCSI devices to a bus that can go so much faster. This of course would involve getting new UW drives along with a new PCI card. So, my first step was to decide on getting a new SCSI card and new hard drives. However the question remained whether or not I would realistically gain anything from using a RAID. I don't use my machine for extraordinary things where high performance would really be necessary. The occasional video capture is the only thing that really would warrant a RAID. I would also like to have speed when working with audio, images and the occasional game. But, the questions remained whether or not my life would be changed from using a RAID. World of SCSI So why upgrade? First, a crash course in disk interfaces. Most PCs, some Macs and most new G3 PowerMacs are shipping with IDE interface. IDE can transfer data at rates of up to 4 MB/sec. However, when connected by a bridge to a local bus, IDE can go up to 13 MB/sec. After consulting with the Amazing Timmer, I believe these higher speeds deal with UltraDMA, which requires matching drives and controllers. I think of SCSI in the terms of four tiers. Regular SCSI-1, which transfers up to 5 MB/sec, Fast SCSI or SCSI-II, which transfers up to 10 MB/sec, and Ultra-Wide SCSI, which transfers up to 40 MB/sec. New on the block is Ultra2 SCSI which offers up to 80 MB/sec. There are variations of these technologies which each yield different speeds. For this review I will concentration on Ultra Wide SCSI. For Ultra2 SCSI information, check out the series of Ultra2 reviews I have online. SCSI Term Bus Width Burst Speed SCSI (I) 8 bit 5 MB/sec Fast SCSI (II) 8 bit 10 MB/sec Fast Wide SCSI 16 bit 20 MB/sec Ultra SCSI 8 bit 20 MB/sec Wide Ultra SCSI (III) 16 bit 40 MB/sec Ultra2 SCSI (LVD) 8 bit 40 MB/sec Wide Ultra2 SCSI (LVD) 16 bit 80 MB/sec Wide Ultra3 SCSI (LVD) 16 bit 160 MB/sec Data Source: Quantum Corp. Depending on what Mac you have, your interfaces will differ. For example in my 8500, I have Fast SCSI on my internal bus and SCSI-1 on my external SCSI bus. So, my internal devices are capable of transfer up to 10 MB/sec on the internal bus, while my external bus is capable of transferring only 5 MB/sec. With the bus speeds in mind, now comes the actual hard drives. The hard drives used in the SCSI system make up the second half of disk access speeds. For this review, I have divided hard drives into four basic flavors based on the RPM speeds of the drive. The common hard drives available to buy today run at 4500 RPM, 5400 RPM, 7200 RPM or 10,000 RPMs. Admittedly I skimped out here and bought into 7200 A/V drives instead of 10,000 RPM drives. I guess the line has to be drawn somewhere. Along with the drive speed, insure the correct interface is installed on the drive. For example, you can use a 7200-RPM drive on a Fast SCSI bus with the correct interface, just as you can use a 4500-RPM drive on an UW bus. This leads into the next critical part of working with SCSI. If you were to put a 10,000-RPM drive on to a Fast SCSI bus, you would not fully utilize the drive's speed. The drive will be faster than a 4500-RPM drive, however it will be limited by the bus speed. Conversely, if you put a 4500-RPM drive on an UW bus, the drive can not perform past its abilities. So the bottom line is, to make an UW SCSI setup on your Mac, you need two parts. You need an UW SCSI card and a hard drive with an Ultra-Wide interface — preferably running at 7200 RPM or faster. In my research, I've found a lot of support for Seagate and their Cheetah drives. While Seagate drives typically edge out Quantum drives in performance, I've personally experienced good performance from Quantum drives, so that's what I stick with. I don't really hold any deep feelings for either company, so I went on a cost/performance basis. The Project As I said, the RAID project was deep in my mind for a number of months. I was working with video more and more, and while I did not want to invest into a capture card (waiting on Iomega I guess) I decided to move my Mac over to an Ultra-Wide disk system. I have been hearing good things about the Initio Miles card, so I decided to pick one up along with three Atlas II drives. My plan was to put all three drives into my Mac and I would have this cool all UW Mac system. I even offered to sell off my old drives to help fund my madness. That was the plan anyway. I was kind of proud of my self, and dropped Mike Breeden a note at Accelerate Your Mac. Occasionally I traded email with Mike talking about my RAID ideas. In actuality, his site really fueled my ambition to try this on my own rather than buy a complete RAID package. After I ordered the SCSI card and drives, I was surfing through his site and read up on his RAID reviews. Mike is working on an "ultimate Mac" where he is attempting to build the best Mac system possible. The RAID Mike built, uses a setup from MacGurus which has a case that channeled quite a bit of air over the drives. This is when I started to think about heat. Basically, I was planning to pancake these drives on top of each other while doing some pretty intensive disk work. They were going to put off quite a bit of heat inside of my Mac. I made a note to call MacGurus first thing Monday morning. Too Much Heat Over the weekend, I took thermometer and put it in my Mac just to see how hot a single 7200-RPM drive ran. To my surprise, it was actually hot to the touch. I mean hot potato hot. In the space around the drive, the temperature was within the operating environment of the drive, however the drive itself as very hot. Quantum lists the drive tolerance at 130 degrees. I used a regular medical thermometer, and it was off the scale at 120 degrees. I suspected the drive was actually running much hotter than 120 degrees since it jumped off the scale in a couple seconds. I then I decided I had a heat problem. I priced a number single and multiple hard disk enclosures from different vendors. The case MacGurus sold definitely took care of the cooling problem. The case has two exhaust fans on the back -- one by the power supply and other for the drives. You can also replace the four bezels on the case with a vented bezel with two little fans. With my four-drive enclosure, I can have four sets of two little fans blowing in and then two big fans blowing out. The result is a pretty good wind tunnel over my drives. For the real cautious, you can put a temperature gage into one of the bezels which will tell you the temperature inside the case. As a bonus, the fans have a fine screen over them to filter out dust and other nasty stuff. After running the case for about a month, the screens were full of dust. The case even runs in a room where a large HEPA air filter runs 24/7. So not only does the case keep the drives cool, but also helps to filter out unfriendly dust. Cooking with Teflon I had a long talk with the people at MacGurus about heat, Teflon and airflow. We were talking about cooking, but rather how to create the best environment for an Ultra-Wide SCSI set up. I had a SCSI card and drives on the way, but suddenly no where to mount them. MacGurus sells a number of enclosures for two, four, and eight external drive cases. The cases themselves are not too expensive, however I found that costs do not end with drives, cards and a case. MacGurus live by SCSI cables made by Granite Digital. They're very expensive, however they are really the best you can buy. At least I would hope so for the price tag. An internal ribbon to support four UW devices retails for $148.99. Once the drives were connected, I also needed an external cable to connect the box to my SCSI card. An external Teflon cable ran me $188.99. That's almost $340 in just cables. As we say, this is were we separate the men from the boys. What's so great about Teflon? If you're really interested, I suggest you hear it from the horse's mouth and give MacGurus a call. We're a few steps deeper than I really want to understand, so I'll give you the short version. Once you pick up one of these cables, you'll, as Steve from MacGurus said, "feel the quality." These cables have 30u" gold contacts and connectors and the external cable is very well insulated. On a SCSI chain, the length of the chain makes all the world of a difference. I once saw someone with a six foot SCSI cable coiled in ball on top of their power strips. They were actually wondering why they were having problems. A long cable is basically a giant antenna looking for interference from other cables and florescent lights. Once you start chaining devices together, your can end up with a lot of cable hanging out there. With Teflon, you can have a little more breathing room with your cables. What that means is where you normally have to be extra careful with your cables, you can get a way with an extra foot or so without running into problems. What also makes the Teflon cables special is they have 90 ohms impedance and .095db per meter max signal attenuation. What this means to non-electric engineers, is the Teflon creates an idea carrier for speedy data. Add this with the solid connectors and you have a pretty sweet SCSI chain. After spending a small fortune on cables, I couldn't forget an active terminator. Termination can make or break a SCSI chain, and I didn't want to skimp out here. Granite Digital has a pretty nifty diagnostic terminator for $98.99. A slippery slope indeed. The RAID There's nothing geekier than building your own RAID. First however a crash course in RAIDs. Simply put, a RAID is when you take two or more hard drives and combine them using software or hardware. Your Mac will use the disks as if they were a single hard drive. A RAID can be used to increase performance, reliability, or do both. There are different types of RAIDs, each of which are ideal for different situations. I'll cover two common types of RAIDs in this review. Striping, or RAID 0, is when two or more hard drives (up to 16 disks per volume over one or more SCSI buses) are linked together. This is ideal for improving performance for disk intensive applications. In RAID 0, if you were to take two 2.2 GB hard drives, you would have approx. 4.4 GB of available storage. I used RAID 0 for this review. The second type of RAID is mirroring, or RAID 1. Mirror RAIDs use two disks at a time to create a redundant copy of your data. If one of the two disks goes down, the computer will continue to operate on the remaining disk which has a mirror copy of your data. There are other types of RAIDs, however these are the two types supported by Conely and FWB. Other than software RAIDs, there are also hardware driven RAIDs. Hardware RAIDs are considerably more expensive and are pretty unrealistic for end users. So when it was all said and done, I had four 2.2 GB Atlas II drives, an UW SCSI card, a kick ass enclosure, and the best cables money can buy. It was time to build my RAID. It took a couple hours just because I was careful handling the internal SCSI ribbon. The Teflon cabling is much more ridged than standard copper cable. Care had to be taken not to bend or twist the ribbon too much. Also, unfortunately my order from MacGurus was missing the external SCSI cable, so I was stuck for a day. MacGurus got it out to me ASAP via over night, however it was frustrating to have this thing built, but not able to play with it. On the upside, it made me take my time building the box. The Tests A couple notes on the tests. I did benchmarks using MacBench and then Norton Utilities for confirmation. FWB RAID required the drives to have FWB drivers installed so I chose not to use FWB tests. I found Conely’s SoftRAID 2 to give significant boost in performance over FWB. As much as 30% at times, so I just stuck with SoftRAID. [Check out Accelerate Your Mac for tests involving different RAID software packages.] Scores were based on publishing tests which showed much more dynamic results that I felt reflected real-world use. The stock machine used for the tests was a PM 8500/180 with 160 MB of RAM. For the G3 tests, a Newer Technology MAXPowr 250/125 daughter card was used. The SCSI card I used was the Initio Miles UW card. Once again, stop by Accelerate Your Mac for comparisons of the different SCSI card out for the Mac. After all the drives were screwed in and everything was hooked up, I installed the Initio card into my Mac and loaded the software. The whole process was nothing to get worked up about -- just a little patience and reading. I ran some tests, and I was pretty impressed with what I found. I tested a single Atlas II drive in my Mac’s internal Fast SCSI bus, and compared the same drive while connected to the UW bus. The single drive came out with a 35% jump in performance. I then hooked two drives together and did a stripped (RAID 0) array. When I hooked two drives together, the array scored 25-30% higher than the single UW disk scores. I knew how fast RAIDs were, but I was actually kind of surprised when I saw it for myself. Curious, I added the other two drives to the array for a total of four disks. When I hooked all the drives up, the RAID was now performing over 100% faster than the single UW drive. When I ran the scores against the Atlas II drive running on the Fast SCSI bus, the 4 drive RAID scored just over 300% faster with publishing tests. So then what about a G3 Mac? I ran the tests using a G3 250 MHz processor, and found an increase of about 20% across the board. Just for kicks, I compared a single Atlas II drive on a Fast SCSI bus running on a 604e 180 MHz processor to a 4-disk array on the G3. The results were a difference of over 400% in publishing scores. Practicality So, adding an Ultra-Wide card and some drives can get a disk system to work a bit faster. I'm using my RAID for three things. First, I've set up three volumes for capturing video, audio, and miscellaneous multimedia work. I've also created a number of 700-MB volumes for CD-R work and general storage. Then I created a volume for high-end applications such as Photoshop. I'm also using a RAID volume for games, however that's more for storage than high-speed access. I did notice difference in performance with Photoshop. Other than a stop watch however, it's difficult to quantify the results. I found Photoshop to boot about 10 seconds or so faster off of the RAID, however I noticed larger improvements in general operations. Using the RAID to run disk intensive application is where the setup can really be utilized on a daily basis. RAIDs are also widely used on networks where large amounts of data are requested simultaneously from multiple users. When you are using a RAID to store valuable data, it is important to consider data reliability. The basis of a RAID is your data is divided across multiple disks. So, in a sense if you have a four-disk array, you are four times as likely to have data loss if a drive goes down. So, what ever you decide to put on a RAID, it is even more so important to back it up. On an application volume like I have, data rarely changes. As an easy back up solution, I just have my application volume backed up onto CD-R. When I add another application to the drive, I just write another session to the CD. For data that changes often, a tape drive would be ideal, or you could use a fixed disk to back up the data as it changes. Steve from MacGurus said he makes a full back up of his RAIDs and then uses Speed Doubler’s Smart Copy to keep his back-ups current on a fixed disk. If data safety is your number one concern, this is where a RAID can also come into play. A RAID could set up as a mirror (RAID 1) to make a redundant copy of your data as it changes. For an example, a couple years ago I was brought in to work on a server on which the hard drive went down. The server had been running unattended for several months, and because the former administrator set up a mirror RAID, the server continued working off of the remaining drive. Conclusions I'm very happy with the setup I built. The case is solid and the parts I put into it are of excellent quality. While it is a rather expensive investment, and there is any number of ways to cut corners, the folks at MacGurus share my philosophy in that, "it works." If you wanted to build your own RAID, I suspect you could go a less expensive route with no problems. If you want the best, and you don't mind paying for it, MacGurus are the people to talk to. It is a big investment, and if I had to do it all over again I would honestly have to consider what to do. As a result, I asked Other Word Computing to also put together a build-your-own-RAID package. I want to stress that both choices have their pros and cons, however I wanted to offer a second option for making a RAID. Other World Computing has generously offered to give Insanely Great Mac readers a discount on a RAID package. The package includes everything I worked with except a different case, non-Teflon cables, and I’ve been told the Atlas II drives are no longer available. Quantum Viking II drives have the same specs, except they are not A/V optimized. They’re also $20 cheaper so its actually a better deal. Their packages include the Initio card I used with SoftRAID 2. Initio Miles PCI SCSI Card w/cables & SoftRaid2 Viking II 2.2gb UltraWide Drives - $495, about $30 off Initio Miles PCI SCSI Card w/cables & SoftRaid2 Viking II 2.2gb UltraWide Drives External in Dual Bay Array Enclosure w/shielded UltraWide SCSI Cables - $595, about $50 off If you choose to build your own RAID from MacGurus, you have no doubt that you’re getting the most for your money versus buying a complete RAID from someone else. While building your own RAID can be expensive, buying a ready-made RAID can be even more expensive. Also when you buy a RAID off the shelf, you don’t know what’s being put into the box. Whether you want to build your own, or have someone else do it for you, MacGurus can help you out. MacGurus has generously offered to give Insanely Great Mac readers discounts on their own RAID projects. The discounts will depend on what you actually buy, however I've been promised those who follow in my foot steps shall be rewarded. When ordering, mentioned you want the Insanely Great Discount. Aside from a processor upgrade, a RAID is the best way to add new performance to your Mac. Prices for SCSI drives and cards are dropping, and this can be an ideal time to upgrade your SCSI or IDE Mac.