I downloaded
Spb Benchmark to find out if the NAND memory is faster or not, rather than have everyone continue to lob forum grenades back and forth. I ran the read/write tests on the main memory and my 8GB Sandisk class 4 SDHC (all times are milliseconds, pasted from the xml results file);
fs=fixed storage
sc=storage card
manyfiles=10KB file x 100
largefile=1MB file
<fs-largefilewrite> 440.600000
<sc-largefilewrite> 1518.500000
<fs-largefileread> 37.100000
<sc-largefileread> 264.600000
<fs-largefilecopy> 492.600000
<sc-largefilecopyto> 326.200000
<sc-largefilecopyfrom> 472.900000
<fs-manyfileswrite> 3919.600000
<sc-manyfileswrite> 4971.400000
<fs-manyfilesread> 385.700000
<sc-manyfilesread> 555.900000
<fs-manyfilescopy> 3482.200000
<sc-manyfilescopyto> 2744.400000
<sc-manyfilescopyfrom> 2811.300000
<fs-dirlisting> 2201.400000
<sc-dirlisting> 214.900000
While some results were about what I would expect (large file tests) the SDHC holds it's own. Someone with a class 6 card should run this and post their results as well.