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> The BCM2711 chip that we use on Raspberry Pi 4 can address up to 16GB of LPDDR4 SDRAM, so the real barrier to our offering a larger-memory variant was the lac
by Legogris 6y ago
> The BCM2711 chip that we use on Raspberry Pi 4 can address up to 16GB of LPDDR4 SDRAM, so the real barrier to our offering a larger-memory variant was the lack of an 8GB LPDDR4 package. These didn’t exist (at least in a form that we could address) in 2019, but happily our partners at Micron stepped up earlier this year with a suitable part.
All other SBCs in this market segments have also been capped at 4GB - I'm hopeful about this leading to larger memory options from other vendors as well before long.
Great of RPi to keep pushing the envelope.
- Zenst 6y agoEDIT - got excited as because I misread and brainfarted GB and Gb and below is what followed - sorry for that folks: Interesting as Samsung developed a 8GB LPDDR4 memory chip back in 2013 - https://news.samsung.com/global/samsung-develops-industrys-first-8gb-lpddr4-mobile-dram https://news.samsung.com/global/samsung-develops-industrys-f... Looking at Micron (who probably tickd the box on price to make this happen), they can do 16Gb modules. So that may well happen. However the power aspect as already indicated from the 4Gb to 8Gb, considerations will prove more interesting. Biggest gain though is more focus upon 64bit, which goes hand in hand with that extra memory.
- dcm360 6y agoThis is a case where you should read with care, and notice the difference between Gb and GB. The chip from 2013 that you mention, has a capacity of 8Gb = 1GB. Chips with a capacity of 16Gb are indeed very common, because manufactures put 8 of them on a RAM-module with a capacity of 16GB.
- Zenst 6y agoMy bad, sorry for that.
- CydeWeys 6y agoHah, that's weird. I can't say I've ever seen memory being quantified in gibibits before! It's always gibibytes. You have to wonder why they deviated from what I thought was a universal custom.
- excelblue 6y agoOnce you work at the electronic components level, RAM (and EEPROMs, etc.) is often specified in bits instead of bytes. The custom of using bytes only applies when specifying higher-level computer components.
- bryanlarsen 6y agoRAM chips are and have always been measured in kibibits and gibibits since long before those two words existed. RAM modules are measured in gibibytes. In a desktop computer you typically use 8 XGb chips to make a single XGB module. The confusion comes when you blur the distinction between chips and modules as they do in mobile. They either use single package modules created from multiple chips via 3D die stacking or they use single chip modules. https://en.wikipedia.org/wiki/Intel_1103 https://en.wikipedia.org/wiki/Intel_1103
- CydeWeys 6y agoThanks for the info. Clearly all my experience in this area is from the perspective of a consumer buying entire modules. I can't say I've ever dived down to the individual chip level.
- greyhair 6y agoIs it true that the L2 cache can only cover the first 1GB of RAM?
- mleonhard 6y agoThe article says that the SoC can handle 16 GB of RAM, so it follows that the L2 cache can, too.