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rbrimhall

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Post Posted November 23rd, 2002, 4:28 pm

when setting cache memory... is this RAM or Hard drive memory... something I've never learned about :oops: This is the pref I'm referring to: pref("browser.cache.memory.capacity", 40096); not the cache available in tools/prefs

Alex Bishop
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Post Posted November 23rd, 2002, 4:39 pm

rbrimhal wrote:when setting cache memory... is this RAM or Hard drive memory... something I've never learned about :oops: This is the pref I'm referring to: pref("browser.cache.memory.capacity", 40096); not the cache available in tools/prefs


That's RAM memory. The pref you're using is setting it to about 4MB. The size of your hard drive cache (hard drive space shouldn't really be described as memory) is accessible from Tools > Preferences and should usually be set to something much higher. Generally, you need both: RAM cache is faster to access while disk cache usually holds more stuff (and has the advantage of being persistent).
Alex

rbrimhall

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Post Posted November 23rd, 2002, 5:06 pm

thanks!! That makes sense! So, when I clear the disk cache I'm not clearing the RAM cache?

daihard
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Post Posted November 23rd, 2002, 6:22 pm

Alex Bishop wrote:That's RAM memory. The pref you're using is setting it to about 4MB. The size of your hard drive cache (hard drive space shouldn't really be described as memory) is accessible from Tools > Preferences and should usually be set to something much higher. Generally, you need both: RAM cache is faster to access while disk cache usually holds more stuff (and has the advantage of being persistent).

Please allow me to jump in. I found the said prefence (pref("browser.cache.memory.capacity", 4096") in ~/phoenix/defaults/pref/unix.js. Now if I add the following line to my user.js, will it override the default setting?

user_pref("browser.cache.memory.capacity", 8192");

I have 1GB of RAM, so doubling up the size of RAM cache shouldn't be a problem. What do you think?

Thanks,
Dai

laszlo

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Post Posted November 23rd, 2002, 8:03 pm

Alex Bishop wrote:
rbrimhal wrote:when setting cache memory... is this RAM or Hard drive memory... something I've never learned about :oops: This is the pref I'm referring to: pref("browser.cache.memory.capacity", 40096); not the cache available in tools/prefs


That's RAM memory. The pref you're using is setting it to about 4MB.

Actually, this pref would set the memory cache to about 39 MB :wink:

daihard wrote:I found the said prefence (pref("browser.cache.memory.capacity", 4096") in ~/phoenix/defaults/pref/unix.js. Now if I add the following line to my user.js, will it override the default setting?

user_pref("browser.cache.memory.capacity", 8192");

I have 1GB of RAM, so doubling up the size of RAM cache shouldn't be a problem. What do you think?

Yes, it will double the default size, and yes, it shouldn't be a problem. BTW: you can always check the prefs that are currently in effect with about:config.

daihard
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Post Posted November 23rd, 2002, 10:11 pm

laszlo wrote:Yes, it will double the default size, and yes, it shouldn't be a problem. BTW: you can always check the prefs that are currently in effect with about:config.

Thanks.

Now, I know this qualifies as another dumb question, but could you please educate me on "about:cnofig"? What is it, and how can I access it?

Thanks again!
Dai

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Post Posted November 23rd, 2002, 10:13 pm

type it into the address bar and hit enter. but make sure you spell it right...

oh, and it's a list of all your configuration settings. if that isn't clear, load it up and it should become fairly obvious what it is.

alanjstr
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Post Posted November 23rd, 2002, 10:26 pm

shimage wrote:type it into the address bar and hit enter. but make sure you spell it right...

oh, and it's a list of all your configuration settings. if that isn't clear, load it up and it should become fairly obvious what it is.


Now only if there was a way to export about:config to a file or to search through it. Sigh. It's on the Mozilla wishlist.

daihard
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Post Posted November 23rd, 2002, 10:32 pm

shimage wrote:type it into the address bar and hit enter. but make sure you spell it right...

oh, and it's a list of all your configuration settings. if that isn't clear, load it up and it should become fairly obvious what it is.

Duh, it's not "cnofig" is it...

Thanks for the info. I didn't realise the address bar can be used this way.

alanjstr
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Post Posted November 23rd, 2002, 10:34 pm

daihard wrote:
shimage wrote:type it into the address bar and hit enter. but make sure you spell it right...

oh, and it's a list of all your configuration settings. if that isn't clear, load it up and it should become fairly obvious what it is.

Duh, it's not "cnofig" is it...

Thanks for the info. I didn't realise the address bar can be used this way.


Just another one of those undocumented features.

Alex Bishop
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Post Posted November 24th, 2002, 3:18 am

rbrimhal wrote:thanks!! That makes sense! So, when I clear the disk cache I'm not clearing the RAM cache?


Yes. I 'm not sure whether your memory cache is cleared when you exit Phoenix or if it's written to the disk cache. I might see if I can find out later.

laszlo wrote:
Alex Bishop wrote:
rbrimhal wrote:when setting cache memory... is this RAM or Hard drive memory... something I've never learned about :oops: This is the pref I'm referring to: pref("browser.cache.memory.capacity", 40096); not the cache available in tools/prefs


That's RAM memory. The pref you're using is setting it to about 4MB.

Actually, this pref would set the memory cache to about 39 MB :wink:


Whoops, missed the extra zero. :-)

daihard wrote:I found the said prefence (pref("browser.cache.memory.capacity", 4096") in ~/phoenix/defaults/pref/unix.js. Now if I add the following line to my user.js, will it override the default setting?

user_pref("browser.cache.memory.capacity", 8192");

I have 1GB of RAM, so doubling up the size of RAM cache shouldn't be a problem. What do you think?


Personally, I have my memory cache set to a quarter of the size of my total amount of RAM. (So I've actually got a larger memory cache than disk cache, which contradicts what I said above. I'm inconsistent like that.) That said, I'm not sure if it actually improves performance. I've never really done any testing to find out the optimum cache size.
Alex

djst
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Post Posted November 24th, 2002, 7:05 am

Alex Bishop wrote:Personally, I have my memory cache set to a quarter of the size of my total amount of RAM. (So I've actually got a larger memory cache than disk cache, which contradicts what I said above. I'm inconsistent like that.) That said, I'm not sure if it actually improves performance. I've never really done any testing to find out the optimum cache size.


Really, what's the benefit of using much memory cache? Is it needed at all? I mean, if you click Back, you will be taken to the previous page you visited, and the amount of time to get that page back in memory from the disk cache shouldn't be more than a second.

Isn't it better to keep the memory footprint of Phoenix as low as possible by <i>reducing</i> the memory cache to a minimum instead?

laszlo

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Post Posted November 24th, 2002, 10:23 am

I think the memory cache (as well as the disk cache) uses a "Least Recently Used" strategy, so it depends heavily on your usage scheme. If you only go back just one or two pages, they will probably be still kept in memory with only 4 MB. If you on the other hand often go back, say, 20 or more pages (or use a lot of tabs), a larger RAM cache will raise the probability that the page is still in memory. I believe I've read somewhere in a related bug that they tested different default sizes, but couldn't determine a further performance gain beyond 4 MB. The real bottleneck with going back and forth is (at least on my box) that the page is re-rendered.

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