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Topics - jiv

1
Hello,
does someone tested CB2 setup with 2 HDD? I have currently one WD Blue 750gb attached to SATA port but i may need soon upgrade space. I am thinking about adding new WD blue 1tb via USB port with something like this.

According to specs it takes 1.4W max, so thats like 380mA, USB should handle it. Also i have 2.5A power source for CB2 (china brand so maybe like 2A+) so i guess it should handle CB2+2xWD blue
2
Software & Applications / Java performance - SF vs HF
August 30, 2013, 10:53:48 am
Hello,
finally got my CB2 so i did some Java tests. Mainly i wanted to test HardFloat and SoftFloat in JVM. I used Cubian Cubian 3.4.43.sun7i+.
lower score is better; test is random float operations with best time from 50 (see attachment).

Results CB2:
jdk7 SF
score: 2247 2202

jdk8 preview HF 
score: 1637 1553

Some other PCs:
i7-Q720(ntb)  - jdk1.6.0_37-x64
score: 1071 723

i5-4670k   -jdk1.7-x64
score: 362 325

All jdk builds are from oracle.

NOTE: in order to run jdk7 SF, you need use multiarch:
dpkg --add-architecture armel
apt-get update
apt-get install libc6:armel


--EDIT: ofc i made mistake in comparing times, fixed results :)

JIV
3
General Discussion / HDD power usage - Watts and Amps
August 01, 2013, 10:29:16 am
Hello,
i want to ask about HDD power usage. I found on eshop site info about power usage of HDDs. Some of them claim 2.5W write, some newer ones (WD blue) report 1.4W.
But how to calculate amps? Since 2.5HDD use 5V, its simple equation 2.5/5 = 0.5A and 1.4/5= 0.28A ?

Is this assumption correct?
Thanks.