Panasonic 512 MB and PNY (Toshiba) 256 MB SD Cards
Posted March 2004 by Tanker Bob

Until I bought my Palm Tungsten|T3, I lived in Sony Memory Stick land for external media needs. The performance amongst Memory Stick offerings holds very uniform. That's far from true for Secure Digital (SD) cards. For an explanation of the various memory card technologies, see here. For their relative specifications, see here. In my experience to date, combined with forum threads on the net, no two SD card brands show greater performance disparity than Panasonic and Toshiba card offerings.

Toshiba seems to enjoy an expanding presence in the repackaging market. Many rebranded cards like the PNY, DaneElec, Lexar, etc., are based on Toshiba underpinnings. DaneElec and Lexar in particular used to be Panasonic strongholds. Economics undoubtedly drive this move, as Toshiba-based cards sell for less than Panasonic-based cards. But what do we give up to save a few bucks? That's the real question addressed in this article, and the answer might surprise you.

About SD Card Testing

First, a word about testing SD card performance. Results depend on many things independent of the card circuitry itself. The card-testing program of choice these days is VFSMark. It turns out that VFSMark results depend to some extent on the free space on the card. For that reason, I tested the cards when newly formatted using CardInfo. Different devices will test differently due to OS and interface overhead. Cards of different manufactured capacities will generally vary in performance depending on the brand.

Also, VFSMark emulates standard Palm OS file operations in that it uses small block memory transfers during testing. This accurately predicts the performance of standard Palm OS file functions, as well as HotSync performance to the card. However, programs like CardExport use large block transfers and can offer radically different performance. In addition, VFSMark results are not absolute values, but are relative to a Palm m500 with a Palm 16MB SD card. The final score consists of an unweighted average, therefore one great result in any area may skew the final score. As a result, total VFSMark scores may not be representative of the user's experience when comparing SD cards. You should always look at the individual test numbers that go into the final score. I'll prove this in a few paragraphs.

I say all this so that users can properly interpret results they find on the net and how those results might apply to their situation. The most applicable results will be those that match your device, card manufacturer, and card capacity. Match as many parameters as you can before taking the information as applicable to your situation. Compendiums of VFSMark test results for various cards and devices can be found here, and T3 results on a forum thread here.

The Test

For consistency with other tests you might find on the net, I used VFSMark 1.1 to evaluate both cards on a Palm Tungsten|T3 (400MHz CPU). I tested PNY (Toshiba) 256 MB (ID SD256 under CardInfo) and Panasonic 512 MB (ID SH512 under CardInfo) SD cards. I ran the tests a number of times on both cards to ensure consistency. I also timed the test to add another point of comparison and to see how close the overall score matches the user's experience.

Test results:

About the results

From the summary VFSMark scores, it would seem as if the user experience from both cards would be comparable. Nothing could be further from the truth. I have enough use on both cards to make some subjective assessments. The Toshiba indeed reads screamingly fast, although in practical use the Panasonic feels just as fast. However, note the disparity in VFSMark test times. The Panasonic finishes the test over 10x faster! My experience shows that the time to complete the test more accurately represents the overall user experience with the Toshiba card.

The first three tests (which involve writing) on the Toshiba take almost all the test time, with the File Write test taking the overwhelming amount of time in that segment. Watching the File Write test progress provides an experience akin to watching grass grow in the arctic. In practical use, USB HotSyncing large files (~10 MB and larger) to the Toshiba SD can literally take over an hour. As long as you're just reading the card, e.g., playing MP3s or looking up data, the card performs very quickly. When writing to it, the card is excruciatingly slow. My old 66 MHz T665C wrote way faster to its 128 MB Memory Stick (VFSMark 98) than my 400 MHz T3 does to the Toshiba SD cards, and that just isn't right.

The exception comes through CardExport 1.14. CardExport apparently writes in large blocks, and the Toshiba chipset is apparently optimized for large block writes. To compensate for the slow HotSyncing to the Toshiba card, I used to copy my daily news in HandStory to the card using CardExport. HotSync took about 5-10 minutes depending on the amount of news, while CardExport took about 15 seconds or so.

On the other hand, the Panasonic writes the fastest of all the cards I've seen tested on the net. Writing to any medium is the most time consuming thing a computing device does, which is why the write tests dominate the VFSMark test time. The Panasonic's 38 seconds test time truly represents the overall user experience. Writing to the card is very fast, and HotSyncing large files proved reasonable (6.5 MB in 4 minutes) even for that inefficient process. BackupBuddyVFS 2.15 took as long for a complete, from-scratch backup (527 files) on the Panasonic as a differential backup (about a dozen or so files) on the Toshiba. Life is good again at Tanker Bob's.

Word of Caution

When you buy third-party cards like PNY, Lexar, SimpleTech, DaneElec, etc., the label doesn't tell the whole story. Sometimes the only way to tell who made the card requires putting it in a PDA and running something like CardInfo on it. When I asked one vendor about a particular card's manufacturer, they told me that the differences weren't significant! I politely disagreed with them. If you want a particular chipset, ask the vendor and ensure their return policy will cover you if what you receive isn't what you expected. Been there, done that…

Conclusions

Several manufactures are marketing new cards touted as enhanced in some way. They go by various names—32x, High Speed, Pro, Ultra, et al. The Kingston Elite Pro High Speed SD cards reviewed here on PDABuyersGuide furnishes just one example. Given the dominance of write performance on the user's daily experience quality, considerable weight should be given to VFSMark's File Write test parameter. The overall VFSMark score doesn't necessarily provide a realistic measure of user experience. That's not to say that some of these cards aren't faster in some areas, but they may not uniformly provide a better overall user experience.

Panasonic clearly dominates high-performance user experiences on the Palm T3, and I suspect other devices, with their standard SD cards. Write performance tops every other SD card currently on the market by a wide margin, while read performance remains very competitive. You'll pay a bit more for a Panasonic than other “standard” cards, but I found the performance improvement well worth the price difference. Caveat Emptor!