简单的说，7xyy中的x，2是GSM/WCDMA，5和6中有一个是CDMA另一个好象是俩都支持的。
yy是20的，就是那个使用了n多年的垃圾货，用在HERO/G1/Sapphire等一系列机器上。
yy是27的，有所改进，但从ARM架构上来讲，是和20在印象里是一代的。
yy是30的，是比8x50还新一代的芯片，用的Adreno 205作为GPU，比1Ghz的8x50要强（但频率稍低）；8x50就是NexusOne的兄弟们。
8x55和8x50a是和7x30差不多的产品。
8x60则GPU是更强的220。
8x7x将是A9的产品（没记错的话是双核）。
Snapdragon is a family of mobile processors by Qualcomm. Currently, all Snapdragon processors are based on ARM Cortex A8 design.
There are currently 3 generations of Snapdragon processors:
1st generation
QSD8x50 - this is the most common Snapdragon processor by far. It runs at 1GHz, and features Adreno 200 GPU. Although considered fast when it was first introduced, now it has been exceeded by many other 1GHz processors. Adreno 200 GPU is especially uncompetitive when you compare it against the competitors with the similar Cortex A8 design. QSD8x50 is manufactured using 65nm manufacturing technology, which once again is uncompetitive by today's standard for high-end processors.
The phones that use this processor includes HTC Nexus One, Verizon's Droid Incredible, HTC Desire, HTC Evo, Dell Streak and others.
2nd generation
MSM7x30, MSM8x55 and QSD8x50A - all 3 variations share the same design, differs only by the clock speeds. These 3 variations run at 800MHz, 1.0GHz and 1.3GHz respectively. Each of these features Adreno 205 GPU which runs at significantly higher performance level than Adreno 200 found in the 1st generation Snapdragon processor.
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MSM7x30 is used by T-Mobile's HTC G2, HTC Desire Z and Verizon's HTC Lexikon/HTC Merge. MSM8x55 is used by T-Mobile's HTC myTouch HD and HTC Desire HD.QSD8x50A is rumored to be used by HTC Mondrian which will feature Windows Phone 7 OS.
All 2nd generation processors are manufactured using 45nm technology.
3rd generation
The 3rd generation line-up is a bit more interesting. Both are based on 45nm manufacturing and features the same Adreno 220 GPU but the similarity ends there.
MSM8x60 - this processor uses the same Cortex A8 design as the 1st and 2nd generation processors. But with the help of Adreno 220 GPU, graphics operations are expected to be MUCH faster. (For more details on MSM8x60, read this article).
QSD8x72 - this processor is based on Cortex A9 design! Cortext A9 is superior to Cortex A8 design and is expected to outperform all Cortex A8 based processors by a significant margin. GPU power should be equivalent to MSM8x60 however.
MSM8x60 based phones may arrive Q4 2010 or Q1 2011. Possible phones to use this processor includes T-Mobile's HTC Glacier and Verizon's HTC Scorpion, and Sprint's HTC Sabor.
QSD8x72 based phones are not expected to show up until at earliest Q3 of 2011. QSD8x72's true competitors are NVIDIA's Tegra 2, Texas Instrument's OMAP4-series andSamsung's Orion platform.
Performance numbers for 2nd generation Snapdragon processors
I assume this is the reason you are still reading this article. 
So how well does it perform compare to other phones of today? Lets look at some benchmark (Quadrant) numbers:
- HTC G2(using MSM7230 at 800MHz) - 1499
- HTC Desire HD (using MSM8255 at 1GHz) - 1974
Now compare these with other phones using stock clock speeds (i.e. no over-clocking allowed here!):
- Droid X with Froyo (using TI OMAP3640 at 1GHz) - 1431
- HTC Incredible with Froyo (using QSD8650 at 1GHz) - 1202
- Samsung Galaxy S with 2.1 (using Hummingbird at 1GHz) - 880 (to be fair, you can apply XDA lag fix to bring this number up significantly, in this case - 2246)
(Source: http://smartphonebenchmarks.com)
As you can see, 800MHz MSM7230 is competitive with other 1GHz offerings. MSM8255 outperforms other 1GHz offerings by a significant margin except for Galaxy S (even though it is only using 2.1), which does feature a ultra-powerful GPU by today's standard (PowerVR SGX540). Could XDA developers find ways to increase 1974 past Galaxy S level? We will find out soon enough.
Updated (Oct 13, 2010): Here's the link to some benchmark numbers for Adreno 205 vs current champ - PowerVR SGX540 used in Samsung's Hummingbird.
Updated (Oct 25, 2010): It appears that MSM7230 is a very good overclocking processor! This is actually not very surprising. Original 1st generation processor found in Nexus One is known to overclock to around 1.2GHz without much hassle. With 45nm manufacturing instead of 65nm, it will overclock at least as well and likely better. As you can see in this table, G2 managed to hit 1.55GHz and produced Quadrant result of 2699 which is 2nd highest to date! I have every reason to believe that MSM8x55 will be able to overclock just as easily.
Summary
So what makes Qualcomm's 2nd generation processors so powerful? We already know that GPU takes a big part in this. Qualcomm claims users will experience 3-4 times the performance improvement over Adreno 200. Adreno 205's theoretical fill rate is still lower than Samsung Hummingbird's GPU rate though, by about 50% level. Without looking at more detailed Quadrant numbers, it will be challenging to figure out where the improvements were made.
My guess?
All of the above mentioned processors are based on ARM Cortex A8 design. They all feature very similar IPC (instructions per clock) numbers. So for day-to-day tasks that do not require graphics, I suspect they will all perform similarly at the same MHz clock speed. GPU is another story altogether. I expect Samsung Hummingbird's PowerVR SGX540 to continue to outperform Adreno 205 by a small margin, but Adreno 205 is definitely outperforming PowerVR SGX530 found in Droid X.
I do expect QSD8x50A to outperform all other Cortex A8 based processors mainly because it is running at 1.3GHz.
Expect phones based on 1.3GHz QSD8x50A to appear during Q4 of 2010.
原来没仔细看，靠三星的Hummingbird打了补丁以后这么强。