I apologize for DOS'ing the list, I can only get online about once a week.
On Wed, 3 May 2017 11:38:26 +0100 Luke Kenneth Casson Leighton lkcl@lkcl.net wrote:
On Wed, May 3, 2017 at 11:28 AM, zap zapper@openmailbox.org wrote:
On 05/03/2017 01:01 AM, Luke Kenneth Casson Leighton wrote:
crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Tue, May 2, 2017 at 10:50 PM, zap zapper@openmailbox.org wrote:
I assume that's going to be the third series of libre cards right? you making a lowrisc based processor and graphics, etc,
more likely the fourth or fifth. all these things happen in parallel. the one after the RK3288 to investigate is the RK3399 (6-core). also i've heard that the iMX7 is out so am having a look at that.
RK3399... 11.0 ghz speed if you count all the four cores which are 2 ghz each and 1.5 for the other ones...
wow...
I wonder how much watts that processor uses...
that is crazy fast. I mean really... 4GB ram too I see as the norm. which is good.
on a different note though, perchance will the fourth or fifth series of libre cards support 8gb of ram or more?
I bet you could even get it to 16gb if you wanted... though that wouldn't be needed. heh.
the cost of the RAM ICs to do that are insane. the 1GB DDR3x16 ICs are already $10 **EACH**.
normally a DIMM would have 8 or 16 RAM ICs, meaning that for a 4GB DIMM you need 8x 512mb ICs, or you could do 8GB by using 16 of them.
But that would mean that an 8GiB stick for a desktop would cost $80 just for the ICs. I can find 8GiB of RAM for $60 and cheaper, I bet, if I poked my nose around. Or maybe desktops don't need ICs???
normally you get 2 (matched) DIMMS totalling 8GB.
if you want *32* GB you get 2 matched DIMMs, but nobody in "mass-production" is shipping windows PCs or laptops with 32GB of RAM (and if they are it's DDR4)
You write that as though being dismissive of DDR4. Why is DDR4 currently unacceptable for one of your designs?
additionally, it would need either 2 pairs of x32 DDR RAM controllers, or it would be necessary to do a cascade layout: a daisy-chain of RAM ICs.... and i'm not sure it would be possible to fit 8 RAM ICs onto the 43x78mm PCB anyway.
bottom line it's far too expensive and quite impractical. 4GB is the practical limit at the moment and even that's stupidly expensive relatively speaking.
l.
Well, I bought a 4GiB RK3399 SOC card fro firefly for $200. Don't get me wrong, I love your effort, but I need RAM, CPU power, lots of ports, and more screen landscape.
Hmm, maybe you should invent an OpenSource IC?
Sincerely, David
--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Mon, May 8, 2017 at 2:07 AM, doark@mail.com wrote:
normally a DIMM would have 8 or 16 RAM ICs, meaning that for a 4GB DIMM you need 8x 512mb ICs, or you could do 8GB by using 16 of them.
But that would mean that an 8GiB stick for a desktop would cost $80 just for the ICs. I can find 8GiB of RAM for $60 and cheaper, I bet, if I poked my nose around.
mass-volume pricing (1m units and above) is radically different from low to mid-volume pricing (1-10k).
Or maybe desktops don't need ICs???
desktops take DIMMs, not individual ICs.
normally you get 2 (matched) DIMMS totalling 8GB.
if you want *32* GB you get 2 matched DIMMs, but nobody in "mass-production" is shipping windows PCs or laptops with 32GB of RAM (and if they are it's DDR4)
You write that as though being dismissive of DDR4.
where did you get that impression?
Why is DDR4 currently unacceptable for one of your designs?
where did you get the impression that i used any words which imply "unacceptability"?
no it's much simpler than you imagined: there simply aren't any ***ACCESSIBLE*** SoCs which have DDR4... yet. "accessible" is defined according to the selection criteria listed here:
https://www.crowdsupply.com/eoma68/micro-desktop/updates/picking-a-processor
Hmm, maybe you should invent an OpenSource IC?
that's what the libre-riscv initiative is about.
l.
arm-netbook@lists.phcomp.co.uk
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Luke Kenneth Casson Leighton