ATP is not as well-known as Sandisk or Lexar but they are leaders when it comes to fast and inexpensive MultiMediaCards.  We tested the 256MB and also made some comparisons with SD and CF cards. Here’s what we found.

First, let’s talk about formats.

To the casual observer it seems that the SD format has overtaken the CF form factor on many platforms and certainly on PPCs. All PocketPCs have at least one slot and that’s an SD slot. With a bit of luck you’ll have an SDIO slot which will take devices other than just SD memory cards. The immediate difference people see when they compare sizes is that the SD card is much smaller. And where do MultiMediaCards fit in? Well, even though they are thinner again than SD cards, they can fit in all SD slots.
So why would you choose MMC over SD cards?
One reason might be that some devices only have an MMC slot, such as certain mobile phones, not an SD slot which can accommodate either size. The thicker casing of the SD card makes it slightly more durable and more resistant to electrostatic discharge. The “Secure” Digital format may seem a bonus for the producers of software, giving them copyright protection, but most consumers would prefer the open systems that CF and MMC have.
However, the SD cards have Write Protection, much like the old floppy disks have. This is good if you need to protect your data from accidentally overwriting it.

This is where the SD seems to have a clear advantage, being able to potentially transfer data up to 10MB per second. This is four times the speed of MMCs. Take note: these are maximum speeds and actual speeds depend on a number of internal and external factors so that some MMCs could possibly be even faster than SD cards. In practice, most devices can’t even handle these transfer rates even though the memory cards can…
So, speed difference may not be all that significant after all.
Our own testing pitted the MMC against similar capacities in CF and SD formats.
Here, the ATP card was faster than Sandisk’s SD but slower (of course) than Crucial’s CF card.
In the end it just may come down to price.  Here, the MMCs do not have to recoup the licensing fee to Panasonic that the patented SD cards carry so MMC should be cheaper.
With recent announcements of 1GB cards on either platform they all have the capacity for a lot of data, images or music.

Conclusion

ATP clearly is the leading producer of MMCs and their website even boasts a very suggestive Read/Write Performance chart that shows ATP clearly in front…
And with our own testing validating that ATP’s 256MB card is no slouch you may have the confidence that these cards will take care of your precious data in the most expedient way!
Pricing: just a shade under USD70 seems to be the current going price for the 256MB card.
And if you want more of the same: we at PocketPCReviews are planning to review the 1GB version as well when its counterpart on SD becomes available too.
Everybody will benefit from more memory and whilst it doesn’t compensate for losing brain cells, the Lifetime warranty is more than what my parents offered me…
 

Speed index = 65.35  

Speed

Storage card "ATP 256MB MMC"
Storage card test results