banbanzon wrote:
有興趣可以看看同為p...(恕刪)
以下是iPaq 110 關於影片播放的報告...看起來PXA310還不錯...參考看看...
Performance
Among its other new features, the iPAQ 110 is also the first device available to have the new XScale PXA310 processor. This is the first generation of new XScale CPUs to be built by Marvell, rather than Intel, after the latter sold off the XScale unit. That said, the PXA310, and its bigger, faster sibling the PXA320, are both still mainly based on Intel hardware and research.
The new PXA310s run at the same clock speed, 624 MHz, as the highest end of the older PXA270 line, and raw floating point performance is almost exactly the same -- 1.9 megaflops for the PXA270, 1.94 for the PXA310, on the Linpack benchmark. That doesn't mean that they're identical, though. Some unconfirmed reports attributed to Marvell claim that the 310 will actually deliver 50 to 100% more performance than a PXA270 at the same speed.
To test this out, I used Spb Benchmark to compare the 110 against my 624 MHz, WM6-upgraded X51v. This isn't a perfect comparison, both since the X51v's WM6 implementation is unofficial, and because it's VGA versus QVGA, but it at least provides some point of comparison.
Most file operations were substantially faster on the iPAQ, as were some graphical operations, though this was to be expected on the lower resolution. In general, I would say that the newer CPU does offer some benefit over the older model in pure performance -- including, at least in my subjective experience, the speed with which the processor spins up to maximum after idling -- but not a life-altering difference.
Regardless of performance, the newer CPUs do boast about two major selling points: improvements in power consumption, and integrated video functionality.
Power first, because it's the hardest to quantify. There's no test that will really tell you how much power is being saved by one component of a device. But some tests on the components themselves have been done by Marvell and others. While playing video, a 624 MHz PXA270 would eat about 530 milliwatts, whereas a PXA320 running at the same speed, playing the same video, only needed 327 mW, a power savings of nearly 40%.
200 milliwatts may not sound like much, but when you figure the fact that that's about 5% of the iPAQ battery's total capacity per hour, it becomes a little more significant. And when you average that over, say, four hours, you're talking about a very significant increase in battery life, 20% or more.
While we're on the subject of processor speeds: Absent on the iPAQ 110, you'll find, is any sort of settings applet for controlling the CPU clock speed or scaling. Never fear, though, because the device seems to do quite a good and aggressive job of this on its own. I found that the 110 does a better job eliminating the fractional startup lag that I associate with the processor scaling up from the power saving 208 MHz "idle" to the snappier 400 MHz to 600 MHz speeds.
The second major selling point of the newer processors is the fact that they include some hardware video decoding capability. Originally, Intel was developing a second generation graphics chip called Stanwood to replace the Intel 2700G (code name "Marathon"). While this project got scrapped before the line was even sold to Marvell, some of the Stanwood features were integrated into the new "Monahans" class processors.
Caution: even more numbers and jargon ahead. If you just want to find out how well it works, without finding outhow it works, skip down a few paragraphs.
According to the specifications, the PXA310 and 320 chips both integrate hardware decoding of MPEG-2, MPEG-4, and some of the more advanced MPEG-4 parts such as H.264. To test this out, I fed the iPAQ a high-quality video clip: 512 x 384, 8 MB per minute, run through The Core Pocket Media Player. I was quite impressed with the result -- It played as flawlessly as it would have on my Axim X51v's hardware acceleration. This despite the fact that TCPMP hasn't been at all tweaked to take advantage of the specific video capabilities of the PXA310, only the older 2700G. Either the new processor handles video acceleration automatically -- a fact which I doubt, given that Windows Media Player doesn't get the same benefits -- or the 2700G tweaks are still compatible.
The system played my first test video so well that I decided to stress it out. I dug up the heaviest video files I had around: 608 x 336 at 13.5 MB/minute, 576 x 384 and 15.8 MB/minute, and last, a whopping 1280 x 720, 27 MB per minute HD clip.
TCPMP actually borked first -- when opening the HD clip, it reported a maximum supported video resolution of 1008 x 1008, and refused to play. Otherwise, all the files worked great, even during extremely high-motion sequences. To compare, an unaccelerated 624 MHz PXA270 on a QVGA device would play the more sedate, low-motion sections of the 8 MB/minute video, but would choke on action or panning sequences.
To test how much leeway there was left, I used the TCPMP benchmark option with the 15.8 MB/minute file. The iPAQ scored 189% of minimum, or a benchmark data rate of 3.1 megabits per second. That means that on the 15.8 MB/minute file, the 110 was only using a little over half its total capacity to play at normal speed.
For comparison, I did the same test on my Intel 2700G-equipped Axim X51v, using the same file, on the same memory card. The Axim scored 277%, or 4.5 megabits per second -- substantially higher, but at a level that could only be significant if you're playing back high-definition video sources. To put it in different terms, the iPAQ should be able to play any file up to 23 MB per minute, which is just shy of 1.4 GB per hour of video recorded. In short, insanely high. And again, I stress that this is without the media player enjoying any specific optimizations to the new processor.
Codec compatibility was equally good. My test sample included files based on DivX, Xvid, and Windows Media Video. Both the DivX and Xvid files worked perfectly. I wasn't able to properly test the WMV file, since the default Windows Media Player does not support hardware acceleration, and TCPMP doesn't support WMV9. However, the chip specifications do list WMV9 playback as being supported.
All stats, numbers, and calculations aside, the iPAQ 110 has tremendous multimedia performance. You can reasonably expect to throw extremely high-quality desktop videos at it and have them play without a second thought. The one thing that's not on the table is hardware-based 3D acceleration and Open GL ES, such as the old 2700G provides. There's still an Open GL driver, but it's now software only. Unless you're into either advanced 3D games or emulators, this won't make a difference to you.
Further, the new design also means substantial power savings on the part of the processor. While this won't translate into an order of magnitude increase in device battery life, it does mean substantial cuts on one of the more power-intensive parts of the device, and less reason than ever before to avoid using a fast processor.
