X-bit labs

AMD Rejects DDR2, Gives Additional Speed Headroom for DDR.

Category: Memory

by Anton Shilov

[ 03/26/2004 | 06:43 AM ]

Advanced Micro Devices is not very positive in regards of DDR2 technology these days because of its high latencies, exceptionally high price and not enough performance benefits. While the co is making its decisions when is the better timeframe to finally support DDR2, its CPUs need a weapon to fight unbeaten memory bandwidth its rival may have with its new DDR2-enabled platforms and, according to sources, this weapon could be faster speed DDR memory.

Official standpoint on DDR2 of Sunnyvale, California-based AMD was said numerous times during various meetings as well as at CeBIT 2004 and was also published at AnandTech recently: “AMD will support DDR2 when it makes sense. This means: when DDR2-667 is introduced and performance advances enough to overcome the DDR2 latency penalty and when the DDR2 price premium fades.”

Historically Athlon, Athlon XP, Athlon 64 and Opteron central processing units benefited a lot from very low latency memory rather than from ultimately high clock-speeds of RAM, unlike Intel Pentium 4 processors, that prosper from tremendous memory bandwidth. Intel’s i915P, i915G and i925X chipsets scheduled for Q2 2004 introduction will sport dual-channel DDR2 at 533MHz memory.

In an attempt to provide high memory system bandwidth for its processors while sustaining low memory latencies, AMD is expected to revamp its memory controller to support memory at speeds beyond conventional 400MHz DDR SDRAM. Some sources in Advanced Micro Devices confirmed additional frequency headroom for AMD’s 64-bit processors with 1000MHz HyperTransport bus, while some sources close to the company said that AMD is readying memory controller that could handle 500MHz DDR modules.

Companies like OCZ Technology and Corsair have been making DDR memory modules at speeds of 500MHz for more than half a year now and are now ramping production of 550MHz DDR as well as 600MHz DDR SDRAM devices. OCZ’s CEO Ryan Petersen recently also expressed very positive attitude towards DDR SDRAM at speeds of 650MHz or higher.

At least some memory module manufacturers now have certain problems with delivering DDR2 modules at speeds of 533MHz, but vow for mass availability of DDR2 at 667MHz sometime in the second quarter of next year. By the same time prices on DDR2 memory are projected to be in-line with prices on DDR memory, some industry sources note.

AMD Athlon 64 and Athlon 64 FX processors with 1000MHz HyperTransport bus are slated for the second quarter launch and will be available in 754-pin and 939-pin PGA packaging. AMD recently said that its desktop AMD64 chips with DDR2 support will also have 939-pin packaging, though, it is not clear whether such processors will be able to work with Socket 939 mainboards made in 2004.

In the second half of 2005 AMD is rumoured to replace its initial 90nm processor for high-end applications, such as Athlon 64 FX or Opteron, code-named San Diego with chip known under code-name Toledo. The latter may sport DDR2 as well as some other innovations, sources familiar with AMD’s plans said.

Official representatives from AMD did not comment on the story.