[RCU] Speed-ups for a slow computer?

Stan Hoeppner stan at hardwarefreak.com
Fri Aug 2 08:17:32 CEST 2013


On 8/2/2013 1:04 AM, Grant wrote:
>>>>>> 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.  

Of course.  I'm simply recommending that you test with HTTP to see if
HTTPS is part of your delay issue.

> Are there any other good
> options for speeding things up besides switching browsers and
> disabling HTTPS?

There may be but we don't have a crystal ball.  You're going to have to
do some testing and process of elimination to figure out the cause of
the problem.  Only then can you identify a solution.

-- 
Stan



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