Best Answer
alacran
,
26 March 2019 - 10:05 PM
We could say that this thread is a continuation of: Making the smallest Win10 install (Wimboot mode) on 512 MB VHD
It was necessary to run some additional test using the info from cdob post No. 95: http://reboot.pro/to...e-4#entry210231
lz4.exe -12 --content-size --favor-decSpeed e:\win.vhd e:\win.vhd.lz4
LZ4 compression is better and faster than using GZ, or any other option, it gave me the faster loading to Ram times, also noticed that when loading from an slow device (as my MicroSD) it has the best efect.
All test ran on same I3 3225, 3.3 GHZ, 8 GB Ram at 1333 MHZ, Rambooting from SSD Adata SU650 into Adata XPG enclosure 3.0 USB.
This are my findings:
Speed:
VHD Time to load on RAM
1 - 10x64-WB.vhd Ramboot using g4d grub4dos-0.4.6a-2018-12-23 12 seconds
2 - 10x64-WB.vhd.gz Ramboot using g4d grub4dos-0.4.6a-2018-12-23 7 seconds
3 - 10x64-WB-EXP.vhd Ramboot using g4d 0.4.5c Modd by kyrionix 4 seconds
4 - 10x64-WB.vhd.lz4 Ramboot using g4d grub4dos-0.4.6a-2019-03-25 3.67 seconds
Saved espace:
VHD Used Saved espace
10x64-WB.vhd 1536 MB 0 % saved espace
10x64-WB.vhd Expandable 480 MB 68.75 % saved espace
10x64-WB.vhd.gz 233 MB 84.83 % saved espace
10x64-WB.vhd.lz4 135 MB 91.21 % saved espace
It is very possible I am getting close of maximum loading speed possible for this PC and this is influencing results.
On a single test I ran from my MicroSD, the 10x64-WB.vhd.lz4 loaded to Ram on 14.68 seconds wich is really a very good time for that device, and it was plugged to USB 2.0
Conclusions:
If Rambooting from a fast device as an SSD use expandable VHDs, they have very good speed and a resonable saved espace, do no require any additional compression, they are capable to Ramboot and also can be booted from Windows bootmanager, so it is not a big issue if they can't boot as Filedisk using grub4dos.
If Rambooting from a not so fast device as an SSD, we have the alternative to use LZ4 compressed VHDs, wich are the faster option and also save more espace than any other option, but they are only usefull for Rambooting, we can not boot them as Filedik using grub4dos or from Windows Bootmanager, this limitations also apply to GZ compression.
Thanks to all members of the forum who collaborated with this thread with info and suggestions, for the realization of all this tests:
antonino61, Wonko the sane, karyonix, tinybit, cdob and yaya for fast fixing grub4dos-0.4.6a-2019-03-25
Just to make a summary of all we have learned/tested/proved/improve on this thread:
From previous Post: http://reboot.pro/to...e-4#entry210209
LZX compressed wim files for Wimboot VHDs do not fail anymore during boot or Ramboot. See: http://reboot.pro/to...am/#entry210021
With this hight compression I have found If we don't add those items on [PrepopulateList], especially the first two we will have troubles during Ramboot
Saving 20 % espace using LZX compressed wim files. See: http://reboot.pro/to...am/#entry210021
Only things we have to do in a different way to reduce about 20 % the size of our source win file is: ..........
Tested GZ compresed VHDs and found they load faster on Ram (almost about 1/2 time).See: http://reboot.pro/to...am/#entry210031
I compressed 10x64-WB.vhd with 7-zip GZ Ultra as 10x64-WB.vhd.gz , it took 15 min, but file is now 233 MB
Saving about 85 % espace if using GZ compresed VHDs, See. http://reboot.pro/to...am/#entry210031
....but file is now 233 MB so it reduced a lot the size 84.83 %,......
Improved speed using GZ compression on VHDs See: http://reboot.pro/to...am/#entry210031
So there is a big improvement in time to load in Ram (43.75 % less time)
Testing expandable VHDs Ramboot capability, and found it was failing.See: http://reboot.pro/to...e-2#entry210068
It fail to load on Ram, still verifiying to try to find if I made a mistake before say it do not work,
Detect the last grub4dos 0.46a version capable to Ramboot expandable VHDs. See: http://reboot.pro/to...e-2#entry210089
grub4dos-0.4.6a-2017-12-20 is last version capable of Ramboot dynamic VHDs, the next version grub4dos-0.4.6a-2017-12-23 Fails.
Thanks to karionix who detected where was exactly the two lines disabled on grub4dos 0.46a after 2017-12-20, See: http://reboot.pro/to...e-2#entry210101
The codes to read hard disk footer in line 185 and read dynamic disk header in line 209 were just "disabled".
Improved again time to load on Ram , using Expandable VHDs. See: http://reboot.pro/to...e-2#entry210074
VHD Time to load on ram
1 - 10x64-WB.vhd Ramboot using g4d v0.46a Dic 2018 12 seconds
2 - 10x64-WB.vhd.gz Ramboot using g4d v0.46a Dic 2018 7 seconds
3 - 10x64-WB-EXP.vhd Ramboot using g4d 0.4.5c Modd by kyrionix 4 seconds
Saved espace using expandable VHDs compared to 1.5 GB fixed size VHDs. See http://reboot.pro/to...e-3#entry210115
VHD Used Saved espace
10x64-WB.vhd 480 MB 68.75 % saved espace
10x86-WB.vhd 360 MB 76.56 % saved espace
8x64-WB.vhd 416 MB 72.91 % saved espace
W864ESP1-WB.vhd 364 MB 76.30 % saved espace
Got the attention of tinybit and yaya (grub4dos development team) and thanks to it, get in about 2 days a new fixed release. See: http://reboot.pro/to...e-3#entry210171
yaya fixed it.
And this new posts related to LZ4 Compression:
karyonix info about LZ4, See: http://reboot.pro/to...e-4#entry210229
cdob info and commands for LZ4, See: http://reboot.pro/to...e-4#entry210231
Analyzing why the difference of speeds: http://reboot.pro/to...e-5#entry210265
Comparing the 2 options suggested by cdob for LZ4 Compression: http://reboot.pro/to...e-5#entry210278
When having x86 and x64 versions you can make a wimboot source wim file with multiple indexes to save espace, see: http://reboot.pro/to...am/#entry210406
And for all lazy people wimb just made a program to make almost all this, things not available on his program are compressions of VHDs and multi-index wimboot source wim files:
VHD_WIMBOOT - Apply and Capture of WIM Files for OS in VHD by wimb: http://reboot.pro/to...-for-os-in-vhd/
And finally now, there is also available this lz4_compressor GUI: http://reboot.pro/to...lz4-compressor/
I only hope this thread has helped some of us to learn something.
alacran
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