Use Invisible Memory as L1 Cache

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mgb
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Use Invisible Memory as L1 Cache

Post by mgb »

Great product so far :D

I'm running WinXP 32-bit on a machine with 8GB of memory, and planned on dedicating the 4GB of Invisible memory to FancyCache, while leaving as much of the memory below 3.2GB for WinXP to use for non-cache purposes.

However, I see that Invisible Memory can only be used for L2 memory, so I must dedicate at least some of the memory below 3.2GB to L1 Cache, then dedicate to upper 4GB as L2 Cache. FancyCache requires at least 128MB for L1 Cache, so I have configured 128KB blocks and a 128GB Cache Size, then Enabled L2 cache for the bulk of Invisible Memory.

First, Is there a better set of configuration values for this setup?

Second, is there a functional reason why the L1 cache can't be placed in Invisible Memory, thereby leaving the lower 3.2GB of memory for programs?
minhgi
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Re: Use Invisible Memory as L1 Cache

Post by minhgi »

I would use 512MB @ 4KB for L1 and the rest for IM for L2.

I have LSI 9260 - 8I that have 512MB Ram onboard with default of 4 seconds write delay.

I use fancycache with the same setting on my Lenovo X220T. Pretty much replicating as a softcaching on the laptop,
mgb
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Re: Use Invisible Memory as L1 Cache

Post by mgb »

Thanks minhgi.

I'm pretty tight in the 'below 3.2GB' region, so the best arrangement for me would be to have a large L1 cache in Invisible Memory. I know that VSuite can build it's RAM-disk in IM without consuming memory below 3.2GB, so I wonder why FancyCache cannot.
minhgi
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Re: Use Invisible Memory as L1 Cache

Post by minhgi »

The developer create the software as intended and is forward thinking . You will no find any other caching program that will use ram and ssd into the concept. I think when the persistent caching is implement, that is where software going to take off.

For now, I would recommend to reduce the L1 to 256MB @ 16K and L2 for IM, as you said that main memory is important to you. 4K and 8k will almost double your overhead use for track and tracing of the cache for L1
robertcollier4
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Re: Use Invisible Memory as L1 Cache

Post by robertcollier4 »

I am interested in the same thing - to use 32-bit windows with 8GB of RAM. I would like to allocate all of my invisible memory to Fancycache and Primo Ramdisk. And leave all of the 3.25 GB possible to Windows applications - but Fancycache insists on using up some 32-bit short supply system memory because "The access speed of system memory is higher than the OS Invisible Memory" (http://www.romexsoftware.com/en-us/fanc ... /help.html). Sure there may be an extra or two PAE lookup tables - but this is unlikely to cause any significant slowdown especially compared to the overhead of having to copy and compare data and keep track of two sets of caches with different priorities.

I believe it should be possible to use only Invisible Memory as L1 cache. The operations of having to move around data between L1 and L2 also seem wasteful if both L1 and L2 are going to reside in physical RAM and it seems it has the potential to unneedlessly clog up the memory bus between all this copying between L1 and L2 memory regions. The speed difference between system memory (< 4 GB) and invisible memory (> 4GB) really can't be that great to warrant this copying, can it? (Also - with PAE enabled - doesn't all the memory, both <4GB and >4GB, go through the PAE Lookup Translation table anyways)?
Manny
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Re: Use Invisible Memory as L1 Cache

Post by Manny »

minhgi wrote: You will no find any other caching program that will use ram and ssd into the concept.
you are not right :)
dustyny
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Re: Use Invisible Memory as L1 Cache

Post by dustyny »

I have to say I'm a bit perplexed why so many here are using 64bit hardware with 32bit OSs. Is this a gaming thing?
robertcollier4
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Re: Use Invisible Memory as L1 Cache

Post by robertcollier4 »

FYI to all following this thread, with new version PrimoCache 0.9.1, it is now possible to use Invisible Memory as L1 Cache.
Hooray.
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