Hello everyone! I've been shopping around recently since I'm looking to finally buy my own computer... And I've run into a question that has gone unanswered for awhile. What's the difference between UDMA 133, ATA 133, and UltraDMA 133 hard drives? And if there is a difference, what should I go with? Do they all accept any type of hard drive? Well, I already know what UDMA is, and a tad bit of ATA... Though I don't know if everything is compatible or not... (By the way, I did search for this answer, but couldn't find a direct answer...) Thanks!

Dear sir UDMA is a technology which accelarate the IDE devices's performance

ATA (Advanced transfer Adapter) 100 vs 133 there isn't much if any difference in speed. <===Lefty===

Ummmm... I don't know if my question was misinterpretated... But... fazil: I stated I already knew what UDMA was... o.O lefty2053: I'm looking specifically at 133 in each, not past transfer speeds. Anyways... I'd just like to know what the differences between each is, if there are any at all. I'm not looking specifically at the transfer speed, but are there scenarios when you might want to use one over the other? Or are certain types of hard drives not compatible with a certain controller? Maybe that cleared it up : )

The ATA/133 IDE interface is backwards compatible with previous interfaces and support all ATA/33/66/100/133 drives. For example, an ATA/66 drive will work with an ATA/133 IDE interface but will still only run at ATA/66 speeds. Of course the reverse is not true. For example, an ATA/133 drive will only operate at ATA/100 if used on an ATA/100 IDE interface. ATA/133, DMA-133, and UltraDMA 133 are different names for the same thing. You will also see UltraDMA 6 and ATA-7 for this mode. Ultra ATA and ATA/133 are tecnologies patented by Maxtor. The reason more drives are not ATA/133 is because drive manufactures would have to license it from Maxtor. Previous technolgies such as ATA/33/66/100 were patented by Quantum but were made freely availably for other manufactures. Ironically Quantum was bought out by Maxtor. Here's where it gets complicated. About the same time as ATA/133 was introduced Maxtor extended the hard drive interface to 48 bits to support hard drives over 128GB. Since motherboard manufactures also needed to support this an ATA/133 IDE chipset standard was adopted which combined support for Maxtor's ATA/133 drives and drives over 128GB (48-bit interface). Soon after the the ATA/100 drive interface was updated to also support drives over 128GB.

Thank you very much, that explains all questions I had.