Returning to our decision to choose controller cards from Promise and SiliconImage, I would like to say that even though we had already collected quite an impressive amount of SerialATA and even SATA-RAID controllers by the time we received HDD samples with 3.01 firmware, we decided to dwell on only two SATA controllers this time. The reason for this decision is very simple: these two controllers have already become very popular (or will become very popular in the nearest future). Both: Promise Technology as well as SiliconImage, not only produce controller cards based on their chips, but also supply their chips to the mainboard makers to be integrated into their products. Today it is simply poor taste to have no integrated SATA/ATA RAID controller onboard :) So, these two companies are really doing great.

3ware and HighPoint controllers were not included into the article because these are RAID-controllers and it doesn't make much sense to test a single HDD with them. The BIOS of a RAID-controller, as well as its drivers are specifically optimized for work with multiple HDDs, that is why in case of a single hard disk drive an ATA RAID controller is usually slower than just an ATA-controller (at least this is what we usually observed by Promise and HighPoint controller cards).

3ware and HighPoint RAID controllers are quite nice solutions, we have already tested them, but we are going to discuss their performance in greater detail in another article :)

Before we pass over to the actual benchmarks results, let's make a few terms clear. Since I don't think it would be a good idea to use the full models names for the hard disk drives tested, like ST3120023A or ST3120023AS, I suggest the following short names indicating the drives, which should be very easy to understand:

• ST380023A = ATA 80
• ST3120023A = ATA 120
• ST3120024A = ATA 120-8
• ST380023AS = SATA 80
• ST3120023AS = SATA 120

Then, since one and the same HDD can be tested with different controllers, the results on the diagram will stand for a combination of a HDD and a controller card. Unfortunately (or, maybe, fortunately), we had to simplify the controller names as well to make them shorter. as a result we got the following combinations for further consideration:

• Promise Ultra100 TX2 + ST380023A= Promise U100 + ATA 80
• Promise Ultra100 TX2 + ST3120023A= Promise U100 + ATA 120
• Promise Ultra100 TX2 + ST3120024A= Promise U100 + ATA 120-8
• Promise SATA150 TX2 Plus + ST380023AS= Promise-WB + SATA 80
• Promise SATA150 TX2 Plus + ST380023AS= Promise-WT + SATA 80
• SiliconImage SiI CP3112SATA150 + ST380023AS= Sil3112 + SATA 80
• SiliconImage SiI CP3112SATA150 + ST3120023AS= Sil3112 + SATA 120

As you may have already understood, Promise SATA 150 TX2 Plus controller formed two combinations with the mysterious abbreviations, such as "WB" and "WT". This is none other but "Write Back" and "Write Through". The matter is that together with the controller drivers we also got a small utility aka Cache Config:

This utility allows changing the controller work mode (caching strategy). Since Promise PDC20375 chip is very unlikely to have a big cache-buffer, I tend to believe that this is all about software cache emulation. To be more exact it should be about some preliminary processing of the on-going requests by the driver, which will definitely eat up some CPU resources. And very soon we will see it with our own eyes.

Before we start discussing the results obtained, I would like to remind you that this is our first practical investigation of the SATA hard disk drives and SATA controller cards performance and features. We haven't yet decided which controllers should be used as reference ones for illustrative HDDs comparison as well as which hard disk drives should be used for controller tests. Therefore, please keep in mind that the results discussed are obtained for a particular HDD working with a particular controller.