NexusHD2 Android Forum

symbuzzer wrote:Our EU HD2's nand memory is very small for new roms you know. For this reason, we are using different installation methods for best performance and flexibilty combination already.
XDA Senior Member Rootdefyxt320 found a new installation method for his HTC Explorer, and shared details with us on XDA.

News Link: http://www.xda-developers.com/android/h ... with-pll2/
Thread Link: http://forum.xda-developers.com/showthr ... ?t=2337886

Maybe we will see this new method on our Leos in next days, who know?

symbuzzer wrote:which is faster format; yaffs2 or ext4? I read somewhere (I couldnt remember now) yaffs 2 is fastest file system format. and I read in another thread/forum that; our nand is like class 5 (?) card but it is faster class 10 ext4 formatted card. because it uses yaffs2.

Today's predominant file system, YAFFS2, will likely be replaced in the future by the likes of ext4, nilfs or f2fs. In order to do a fair comparison one must compare I/O throughput, user data access latency, application execution latency and data safety. Not a simple task.

If you ever want to get Linux techies arguing just talk about which file systems are the best.

Google, which knows a thing or two about fast systems, has decided, for their purposes anyway, that Ext4 is the best and close to the fastest file system of all. Google also hired Ted T'so, who also happens to be the leading Ext4 programmer. In a note to the Ext4 developer mailing list, Google's Michael Rubin, a senior staff engineer, wrote, "Google is currently in the middle of upgrading from ext2 to a more up to date file system. We ended up choosing ext4." So, if you are using an Android phone and you are not a kernel developer you may want to take Google's word for it, at least for now, and go with the ext4 file system on your SD Card.

In all fairness, the numerous tests that have been ran over the years will prove different winners. Some show ext2 to slightly outperform ext4 but we must also consider data safety and journaling. While not many of us will have vital, enterprise data on our mobile devices, reconfiguring and restoring a device can be tedious, at best. Some will argue for NILFS, others for ext4, and yet others.. well, you get the idea.

NYLimited wrote:
I am a little confused. Admittedly, I have only did a cursory read of the topic on XDA but much of what is described (e.g. moving /data and /cache to the card) is already available to us via the DataOnEXT install method of Tytung's ROMs.

Changing the overclock frequencies could be done by most though it is questionable if it is healthy for the device or not. I am not personally convinced this would give an HD2 a new and long life but I suppose people will try it.

tytung wrote:
Yes, we have already moved data and cache to the SD card via the DataOnEXT install method.
We even have NativeSD which moves data, cache and system to the card.
We have a OCed kernel too. But I'm not sure if PLL2 overclock or PLL4 overclock was used.

symbuzzer wrote:ok, I understand. so, why did Rootdefyxt320 find/release this? what do you think about it?

cute_prince wrote:http://forum.xda-developers.com/showthr ... ?t=2337886
In case of HTC Explorer, it uses Qualcomm MSM7225A chipset. This chipset does not have PLL4 support. So the only way to overclock is by OC'ing PLL2.

symbuzzer wrote:ok, I understand. so, why did Rootdefyxt320 find/release this? what do you think about it?

symbuzzer wrote:

what are pll2 and pll4 overclock?

cute_prince wrote:XDA user @rootdefyxt320 has written an excellent post that tells the exact difference between PLL4 OC and PLL2 OC. I am quoting it:

PLL2 overclock can be compared to FSB overclocking in computers i.e locked multiplier overclocking in the BIOS. FSB overclocking involves overclocking of the PC buses such as the Memory Bus, PCI/ PCI-Express bus and AGP buses (older computers) and the CPU. It works out by XXXXMHz multiplied by X multiplier and that will give the CPU speed. PLL2 overclock does the same thing because PLL2 controls the bus speeds (exists in the SOC). It overclocks the memory buses, SOC clock, internal storage (database IO) speed and of course the CPU. It works out by XX multiplied by 19/2 and that gives the CPU speed. That's why PLL2 on 800MHz is faster in performance than PLL4 on 800MHz . Therefore that's the reason why people complain of burnt NANDs on HTC Explorer and Motorola Defy Mini XT320/321.

PLL4 overclock can be compared to unlocked multiplier overclocking where you adjust the multiplier in the BIOS and it will automatically adjust the clock speed depending on the multiplier of the CPU. Therefore this only overclocks the CPU. PLL4 overclock only overclocks the CPU and NOT the buses so it can go at much higher frequencies than PLL2 overclock. PLL4 overclock does NOT adjust bus speeds so therefore it is much safer to overclock and it doesn't burn out your SOC.

cute_prince wrote:In case of HTC Explorer, it uses Qualcomm MSM7225A chipset. This chipset does not have PLL4 support. So the only way to overclock is by OC'ing PLL2.