[RCU] Speed-ups for a slow computer?

Grant emailgrant at gmail.com
Fri Aug 2 08:04:13 CEST 2013


>>>>> Can anything be done to speed up Roundcube on a Celeron 700 with 512MB
>>>>> RAM (maxed out) running Gentoo Linux?  We're using the Chrome browser
>>>>> and the CPU is 95% idle when no one is logged into X.  I'm getting
>>>>> reports of 30+ seconds to open an email.
>>>
>>>> Your problem is likely the amount of RAM; when you start X and Chrome,
>>>> your client almost surely starts swapping, because there isn't enough
>>>> RAM for the running processes. Roundcubemail uses AJAX which requires a
>>>> fast javascript interpreter, and this makes things worse if your
>>>> processes (including Chrome) are swapping.
>>>>
>>>> On such low-end systems you should use a very lightweight browser
>>>> instead of Chrome, even if this can give some limitations.
>>>
>>> This is simple to check.  With all apps running simply run "free -m" and
>>> post the output here.
>>
>> Here's what I get while someone is seated at the system and using
>> Roundcube in Chrome:
>>
>> # free
>
> Using the "-m" switch displays output in megabytes--easier to read.
>
>>              total       used       free     shared    buffers     cached
>> Mem:        513072     447812      65260          0      16896     209672
>> -/+ buffers/cache:     221244     291828
>> Swap:      2097148          0    2097148
>
> This clearly shows the host isn't using swap, has 64MB free, and is
> using ~200MB for buffer cache.  So it seems to have plenty of memory.
>
> JVMs and JAVA are notoriously inefficient, but that should cause a 30s
> delay just opening a new email.  Using HTTPS and JAVA together may be
> enough to bring a Celery 700 to its knees.  Try using straight HTTP
> instead to eliminate the encryption.  This will make a big difference
> with binary attachments such as photos and the like.  With small text
> only emails it shouldn't cause a big delay.

I'd rather stick with HTTPS if possible.  Are there any other good
options for speeding things up besides switching browsers and
disabling HTTPS?

- Grant


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