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New DDR5 SDRAM standard supports double the bandwidth of DDR4

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JEDEC, the controlling body of the RAM standard, has published details about the DDR5 SDRAM spec to address the demand for ever-faster RAM.

The new DDR5 spec is designed to enable scaling memory performance without degrading channel efficiency at higher speeds. This was done by doubling the burst-length to BL16 and bank-count to 32 from 16. DDR5 DIMM also has two 40-bit independent sub-channels, increasing efficiency, and reliability.

A new feature deemed Decision Feedback Equalization (DFE) enables IO speed scalability for higher bandwidth and performance improvement. DDR5 supports double the bandwidth of its predecessor, DDR4 with 4.8 gigabits per second possible — but not shipping at launch.

DDR5 also supports on-die ECC scaling features, which enable manufacturing on advanced process nodes.

"The DDR5 standard offers the industry a critical advancement in main memory performance to enable the next-generation of computing required to turn data into insight across cloud, enterprise, networking, high-performance computing and artificial intelligence applications," said Frank Ross, JEDEC Board of Directors member and senior member of Technical Staff at Micron.

Power requirements were dropped from 1.2V to 1.1V compared to DDR4. A voltage regulator on DIMM design reduces power consumption and offers better voltage tolerance for better DRAM yields. DDR5 uses the MIPI Alliance I3C Basic specification for system management bus.

"DDR5 is prepared to improve the Computing Performance by applying various features to overcome future technology scaling challenge and improve performance compared to DDR4. On this basis, DDR5 will lead the evolution of the data-centric era, and will play a pivotal role in the 4th Industrial Revolution," said Uksong Kang, Head of DRAM Product Planning at SK hynix, one of the JEDEC members. "SK hynix is opening up a new sector in the market through the development of the industry's first DDR5 that meets JEDEC standards. We have been working with many partners to verify DDR5 Ecosystem through development of test chips, and modules since 2018, and doing our best to secure mass-production levels in the second half of this year."

The product is expected to arrive in data centers and other cloud computing applications first, and migrate to consumers shortly thereafter. JEDEC has made the spec available for purchase.



9 Comments

Xed 5 Years · 2904 comments

A bit off topic, but I'm looking forward to Si allowing us (the consumer) to have devices with faster RAM without waiting forever for Intel to adopt it.

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viclauyyc 11 Years · 847 comments

Xed said:
A bit off topic, but I'm looking forward to Si allowing us (the consumer) to have devices with faster RAM without waiting forever for Intel to adopt it.

Don’t think that will happen in portable Mac line. Apple is hooked on soldering on ram. 


But it could happen in desktop Mac. 

Xed 5 Years · 2904 comments

viclauyyc said:
Xed said:
A bit off topic, but I'm looking forward to Si allowing us (the consumer) to have devices with faster RAM without waiting forever for Intel to adopt it.
Don’t think that will happen in portable Mac line. Apple is hooked on soldering on ram. 
But it could happen in desktop Mac. 

You don't think LPDDR4 will be coming to Mac notebooks? I'd be surprised if the next Si Mac notebooks are still using LPDDR3 RAM.

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flyway 5 Years · 1 comment

GPUs such as the AMD Radeon Pro 5500M use GDDR6 and the 5600M uses HBM2 in the 16" MacBook Pro.
Is DDR5 mainly for the CPU and how does it compare to GDDR6 and HBM2?

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tht 24 Years · 5673 comments

flyway said:
GPUs such as the AMD Radeon Pro 5500M use GDDR6 and the 5600M uses HBM2 in the 16" MacBook Pro.
Is DDR5 mainly for the CPU and how does it compare to GDDR6 and HBM2?

It depends on how many channels of each memory.

2 channels of DDR4: 50 GB/s
2 channels of DDR5: 100 GB/s
2 channels of GDDR6: 250 GB/s
2 channels of HBM2: 1000 GB/s

DDR5 is for system or main memory for PCs, servers and such, but it usually comes down to cost. If HBM was cheap, there would be systems using it for main memory, but it is two expensive to be used as system memory for a regular PC. It will be interesting if Apple uses it as main memory for high end Apple Silicon Macs though. I'm almost half expecting it.

There are latency differences that can sway usage of one type of RAM over the other depending on primary application as well.

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