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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: sim085 on April 02, 2016, 07:14:16 PM

Title: Question on old RAM
Post by: sim085 on April 02, 2016, 07:14:16 PM
I have some old 30 pin SIMM 1MB sticks. I was wondering; how can I know their speed?

On eBay I saw that 256 KB sticks are marked as 120ns. I would like to buy some new sticks. However I would like to know what is the max speed possible and the speed of my sticks.

Also; does it make a big difference?
Title: Re: Question on old RAM
Post by: Zardoz on April 02, 2016, 08:00:19 PM
can you post a pic of the memory. most like going to be 80 to 120, sometimes you can look up the memory and get the specs.

really the different in speed on Amiga systems is not going to madder that much. if it's 80ms I would not fuss over it.
Title: Re: Question on old RAM
Post by: Oldsmobile_Mike on April 02, 2016, 09:25:12 PM
I would always use the fastest possible, within reason.  Maybe it's more of a "feel good" thing, than anything else.  But if you system is heavily accelerated it might help.  ;)

Look for the last digit on the chips, something like a -80, or -8, that might help you.  Or, yeah.  Just post a picture.  :)
Title: Re: Question on old RAM
Post by: mongo on April 02, 2016, 10:37:01 PM
The speed of a memory chip is the fastest speed that it can be accessed at. As long as the chips you're using are as fast or faster than the device you're using them in was designed for, there is no problem. Using faster chips won't improve the speed. Using chips slower than the device was designed for will cause problems.
Title: Re: Question on old RAM
Post by: QuikSanz on April 02, 2016, 10:49:11 PM
A bit faster then the system is good, the CPU won't have to wait!
Title: Re: Question on old RAM
Post by: Zardoz on April 02, 2016, 11:34:51 PM
Quote from: QuikSanz;806716
A bit faster then the system is good, the CPU won't have to wait!


30 or even 40 ms in ram is almost nothing,.. I would doubt if you would even perceive it old systems like this. mongo is also very correct with his statement.

old memory speeds does not act like today's memory.
Title: Re: Question on old RAM
Post by: QuikSanz on April 03, 2016, 02:19:25 AM
Quote from: Zardoz;806719
30 or even 40 ms in ram is almost nothing,.. I would doubt if you would even perceive it old systems like this. mongo is also very correct with his statement.

old memory speeds does not act like today's memory.


Lol, 40 is darn fast. I use 60ns on my accellerators.
Title: Re: Question on old RAM
Post by: mechy on April 03, 2016, 04:57:06 AM
Quote from: sim085;806707
I have some old 30 pin SIMM 1MB sticks. I was wondering; how can I know their speed?

On eBay I saw that 256 KB sticks are marked as 120ns. I would like to buy some new sticks. However I would like to know what is the max speed possible and the speed of my sticks.

Also; does it make a big difference?

what most said is correct, just look on the chips on the simms and they will have -6,-8 ,-12 etc on the end number,which is the speed, 60ns,80ns,120ns etc

Nano seconds guys,not ms(milliseconds)..
ms in ram would be horrible slow ;)
Title: Re: Question on old RAM
Post by: sim085 on April 03, 2016, 09:50:58 AM
Thanks for the replies. I believe my question is answered. However since some asked for pictures I took the sticks out and took some. The first two end with J70 ... that means 70 ns?

So 40ns is better than 120ns?

if that is a yes then for something like this:
http://amiga.resource.cx/exp/impact500mk2

Where it says "accepts 1 or 4 MB 120 ns SIMMs"

What happens if you put a stick of 40ns? it runs at 120ns?

From the answers I know this most probably does not make much of a difference but still curious :)
Title: Re: Question on old RAM
Post by: zipper on April 03, 2016, 11:28:08 AM
Even the fastest accelerators using 72pin SIMMs did use 60-70ns. 50ns (expensive,rare) was needed on some heavy OC cases. So 80 - 120 was probably common on 30pin accelerators. Faster than default memory doesn't give any speedup, it runs on default speed.
Title: Re: Question on old RAM
Post by: vince_6 on April 03, 2016, 11:43:46 AM
Last year I red again my blizzard's manual (030/50).
I saw this line " 70-60ns or better"
So a good friend gave me a 50ns 8MB ram, I was surprised as AIBB gave better results on some bechmarcks.
Title: Re: Question on old RAM
Post by: zipper on April 03, 2016, 12:55:10 PM
Might be that 50ns could run better than a mediocre 60ns which fails to perform as expected.
Title: Re: Question on old RAM
Post by: delshay on April 04, 2016, 04:10:04 PM
If you want the fastest classic memory, you have to build it yourself or get a expert to build it for you.

I own the fastest 72 pin EDO memory in the world ( 4x 128MB ) 28ns, speed binned with every error I can detect removed.

The EDO memory I have here, was built from the out-set with the lowest timing in mind. I could do the same to any classic memory, but it cost a lot to get it right.

Now working on DDR1, but I have ran into problems, no access to TCRD.
Title: Re: Question on old RAM
Post by: Zardoz on April 04, 2016, 05:05:13 PM
basically you want to use memory at the speed the device is rated for or better. for instance lets say the card spec is to use 80ns memory.  you then should use 80ns our lower memory like 80, 70, or 60, as it will all run fine in that card. however putting in slower memory like 120ns can result in memory issues as the memory would not keep up with the demands of the card.

some older device had jumpers that you could set for the speed memory you was to use. like a settings for use of 120ns or 80ns this is so you could use almost use any memory you have or could get as long you could set it.

now days memory speed is handled much differently and more automatically with out the use of manual jumpers.
Title: Re: Question on old RAM
Post by: Zardoz on April 04, 2016, 05:09:55 PM
Quote from: sim085;806742
Thanks for the replies. I believe my question is answered. However since some asked for pictures I took the sticks out and took some. The first two end with J70 ... that means 70 ns?

So 40ns is better than 120ns?

if that is a yes then for something like this:
http://amiga.resource.cx/exp/impact500mk2

Where it says "accepts 1 or 4 MB 120 ns SIMMs"

What happens if you put a stick of 40ns? it runs at 120ns?

From the answers I know this most probably does not make much of a difference but still curious :)


can you get more of a macro shot I cant read them.
Title: Re: Question on old RAM
Post by: sim085 on April 05, 2016, 08:39:10 PM
I attached better photos. The last digits of each are; 70, 12 (I suppose means 120), 7 (I suppose means 70) and 50.

Quote from: Zardoz;806804
can you get more of a macro shot I cant read them.

I did a search on ebay; couldn't find any 50ns ... that said, it would be useless to buy 50ns for a GVP HD8+ given the limit of 120ns. Is this right?
Title: Re: Question on old RAM
Post by: Oldsmobile_Mike on April 05, 2016, 09:51:53 PM
Quote from: sim085;806834
I did a search on ebay; couldn't find any 50ns ... that said, it would be useless to buy 50ns for a GVP HD8+ given the limit of 120ns. Is this right?

You still have that backwards.  Lower numbers = faster, higher numbers = slower.  120ns is the slowest you can go, but it would never hurt to go faster.  I have 60ns in my GVP sidecar and it works great.  Think I paid about $7 each for a pair of newly manufactured (probably remanufactured - old chips on new boards) 4MB 60ns 30-pin SIMM's a few years ago, and they work great.  :)
Title: Re: Question on old RAM
Post by: Oldsmobile_Mike on April 05, 2016, 09:55:22 PM
For a GVP sidecar you want something like this:

http://www.ebay.com/itm/4x-4MB-Samsung-30pin-tin-non-parity-SIMM-memory-low-profile-tested-Apple-Amiga-/182081428205

Doesn't necessarily need to be this listing, but you get the idea.  30-pin, 60ns.  I like the ones with fewer chips (less parts to fail, less voltage/power requirements, blahblah, etc.).
Title: Re: Question on old RAM
Post by: Oldsmobile_Mike on April 05, 2016, 09:58:33 PM
Here's two that should work for the princely sum of $12 USD, with free shipping.  ;)

http://www.ebay.com/itm/2x-4MB-Samsung-30pin-tin-parity-SIMM-memory-low-profile-tested-RAM-386-486-PC-/172150483700
Title: Re: Question on old RAM
Post by: Zardoz on April 06, 2016, 12:16:41 AM
Goldstar look to be  1MB 70ns
Mitsubishi look to be 120ns was not able to read part number.
MT= Micron, was not able to read part but looks like -7 on the end most like 70ns
The last one unreadable.

I can tell you some parts don’t like that 3 chip memory I remember some stuff not liking it, it just depends.
Title: Re: Question on old RAM
Post by: Oldsmobile_Mike on April 06, 2016, 03:58:02 PM
Quote from: Zardoz;806850
I can tell you some parts don’t like that 3 chip memory I remember some stuff not liking it, it just depends.

Actually it looks like mine are only 2 chips, based on this picture I took a few years ago.  Obviously the label is covering them, but looks like only two would fit under there.  What can I say, haven't cracked the old gal open in a while.  ;)

Also, we gotta get you guys some better cameras.  It never ceases to amuse me how often Amiga users (who I'd consider to be "pretty geeky") don't have a whole rack full of good camera gear (another "geeky" hobby), haha.  :)
Title: Re: Question on old RAM
Post by: Zardoz on April 06, 2016, 05:09:33 PM
2 chip is the same just does not have parity. memory that had 2 chip like that or 8 chip tends to be non-parity memory.