[squeak-dev] Re: Smalltalk and flash memory
Lou at Keystone-Software.com
Sun Jun 8 20:50:44 UTC 2008
>Your comments about not having to intentionally manage writes of objects
>indicates that you believe that the read/write/erase characteristics of
>flash memory are similar to conventional memory. Cells in flash memory
>can't be re-written without first erasing. Erasure occurs on block
>boundaries. You can only erase a block a certain number of times (typically
>in excess of 100,000). I find it convenient to think of flash as a very
>fast replacement for disk drives. Compared to disks, it has very fast read
>access, especially for random reads, but the block structured erase/write
>protocol look more like a disk drive. See
>http://en.wikipedia.org/wiki/Flash_memory for more.
I am being a little sloppy calling the persistent memory I'm talking about
"flash memory". I of course don't mean the exact kind of flash memory used for
memory sticks or disk drive replacements. You are correct about their block
nature and that is clearly not what I want. NOR flash memory is what I am
Maybe I'm looking too far into the future but NOR flash memory is here today and
I think the prices are coming down. I would like to generate a conversation
that might show a need for this memory and motherboards that support it, sooner
rather than later.
>Object persistence managers like GemStone, Glorp, etc, are still needed, but
>flash memory will definitely change the way we think about persistent
They are still and will be needed for quite some time. Again I'm trying to push
things a little here. NOR flash memory is used in PDAs. I think there is a use
for it in laptops and the use I described for servers.
>PS - I did a quick search to see if there have been any breakthroughs in
>flash other than price/density and didn't find anything. If anybody has
>more info on this, please pass it along.
Try looking for NOR flash memory. The price and sizes aren't where I want them
but we can still look toward the day that they will be and think about the VM
changes needed to use NOR flash memory.
>On Fri, Jun 6, 2008 at 5:50 PM, John M McIntosh <
>johnmci at smalltalkconsulting.com> wrote:
>> On Fri, Jun 6, 2008 at 3:24 PM, Louis LaBrunda
>> <Lou at keystone-software.com> wrote:
>> > A Smalltalk program running on a server with a large amount of flash
>> > could run without the need for another form of database. The flash
>> memory would
>> > be in addition to the normal memory, with both available as RAM. The
>> > memory would not look like a hard disk replacement.
>> You might want to do some reading about GemStone
>> It does much of what you discuss. They have a free version so you can
>> explore more how it behaves.
Keystone Software Corp.
mailto:Lou at Keystone-Software.com http://www.Keystone-Software.com
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