BIj AnandTech is een aardig artikel online gezet waarin Ultra ATA/33 en 66 harde schijven vergeleken worden. Er worden bergen benchmarks gedraaid (25 pagina's benchmarks!)onder Windows 98SE, NT4 en 2000. Hieruit blijkt dat Ultra TA/66 op dit moment nog niet zo'n snelheidsvoordeel heeft, maar dat het in de toekomst belangrijker kan worden:
In general, if you are still using an Ultra ATA/33 system, with the current generation of drives there is not really an incentive yet to switch over to the new interface. We do expect the forthcoming drives to start utilizing the increased bandwidth the Ultra ATA/66 interface affords and defiantly see the need for its implementation. However, as you can see from our testing, there is currently little performance benefit using one interface standard over the other.
As mentioned previously, the Ultra ATA/66 specification should be viewed more as a way of allowing room for growth in hard drive transfer bandwidth, than it is for a current performance booster. To put it in simpler terms, itís akin to adding 4 more lanes to a highway that currently is able to handle 5000 cars per hour. If that highway only has a current peak usage of 5000 cars per hour, and all the cars are able to maintain a 60 MPH speed, then the addition of those extra 4 lanes will not be immediately noticeable. But in 5 years time, when the traffic has doubled to 10,000 cars per hour, the average speed will be able to be maintained at 60 MPH instead of reducing the traffic flow to a crawl had the changes not been previously made.
Although there are other factors in traffic flow patterns besides the number of lanes, and hard drive interfaces are not highways, we hope that you can see the point in the analogy. While the Ultra ATA/66 specification is definitely needed, and in some limited situations, you can currently see a slight benefit, it is definitely more of a technology that allows room for growth in the future than it is for offering enormous performance benefits today.