RAM

Posted by: PaulWay

RAM - 11/09/2000 05:26

Empeg-type people: A couple of questions about storage and stuff.

Firstly, what's the tradeoff that stops you putting more RAM on board? Price? Board space? Is there little extra benefit in keeping the hard disks spun down that little longer? Because some of the applications that people want to run on the machine - FTP, Samba, HTTP streams, etc. - are going to be pretty memory hungry, and making a box that can cope with all these applications on the desktop and still function as a decent player in the car seems to me to require more RAM.

Secondly, is there any limit to the number of times you can write to the NVRAM (or wherever you're using as long-term writable storage for playlists, etc)? I've heard that some NVRAM chips (or maybe it was EEPROMs) deteriorate and start getting errors after a (large) number of writes. There's a number of applications, such as storing user preferences and other data, that seem to me to require pretty regular use (e.g. one write per track played) over the life of the player. And how much of this storage do we have? What about looking into getting a microdrive into the machine to store that sort of stuff?

Thirdly, is there any ETA or indication of when the larger (25GB, 30GB) drive sizes are going to become available? As (it seems) a lot of your customers are ordering the largest size available, I'm sure they will be looking forward to hearing some announcement along these lines. While my needs are not that grand, I would like to purchase a player with one drive so that later, when my music collection has grown, I can purchase another drive (which, at that stage, will probably be in the 50GB range...) and continue growing.

Have fun out there producing the greatest car audio product to hit the market since speakers.

Save the whales. Feed the hungry. Free the mallocs.
Posted by: altman

Re: RAM - 11/09/2000 05:37

Board space is the main constraint currently, yes. We have a large number of 16Mbit EDO chips which we're using at the moment. 12Mb is 6 chips, which is a large amount of area. Going to double-sided assembly is very expensive, so everything has to stay on one side. The next move will be to a CPU capable of SDRAM support, but this won't be for a while yet - at that point, we'll probably go to 16Mb. 32Mb is possible, but pointless for the vast majority of users (they'd never notice the difference) - DIMM support isn't really very practical due to many constraints including capacitive loading of the bus (ie, we'd need to fit bus buffers, etc).

Our flash has 100,000 erase cycles minimum. We only write to this on power down, not on track skip, so you're looking at 100,000 power cycles which is a *long* time... playlist info is written to disk. The flash does both kernel/ramdisk storage and parameter storage (/dev/empeg_state - current track & timecode in playlist, volume, etc).

Bigger drives: when we can get them easily, and guarantee supply, we will offer them. At the moment we can get samples but not supply. No idea on when we'll be able to get them properly as dates given by IBM have little relation to calendar-time :)

Hugo


Posted by: PaulWay

Re: RAM - 11/09/2000 16:17

Another question about more RAM:

Is there any indication that constantly activating and deactivating a hard disk increases its wear? An extra strain on the motors or spindles due to torque? Not that I expect that there's much danger at the moment, but in the interests of curiosity...

As to the playlist write, this mechanism of last-minute writing as power goes down seems to work very well at the moment. How much extra information could be written in the time available? For instance, if I wanted to write an application which would keep a track of transition ratings (see the wish list), would it too be able to write its table out to disk at power-fail? Or is there not enough time to write to two files? I can see this being a big issue for people writing other applications on the empeg...

We'll wait with bated breath for the new drives :-)

Paul

Save the whales. Feed the hungry. Free the mallocs.
Posted by: tfabris

Re: RAM - 11/09/2000 16:37

As to the playlist write, this mechanism of last-minute writing as power goes down seems to work very well at the moment. How much extra information could be written in the time available?

Only a few bytes get written to NVRAM at power loss time. It basically keeps track of where you were in the current playlist, plus a couple of other little things.

It's doesn't do any disk operations at power loss. For instance, when you begin playing a new shuffled playlist, it writes that into scratch space on the hard disk at the time you begin playing it, not at power down.

At least this is the way I understand it to work.

___________
Tony Fabris
Posted by: altman

Re: RAM - 11/09/2000 17:04

Spin up/down cycles do affect drive life; however, specs from the manufactuers are typically 300,000 cycles, which gives several years of constant use. By the time the drives wear out, you'll wonder how you managed with less than 300Gb ;)

Hugo


Posted by: tonyc

Re: RAM - 12/09/2000 05:16

300 GB of MP3's.... *drool*

I wonder if I could even amass that much music in my lifetime... But I'd have fun trying!

---
MkII 080000554
Posted by: dionysus

Re: RAM - 12/09/2000 09:51

I'm willing to bet by that point it'll be music videos instead of just music..
-mark

MK2: 36gb
Tivo: 90gb
CPU: 120gb
...I think drive manufacturers love me!