Help~Is~Here
Banned
Source: Anandtech.com
Link to Article: *www.anandtech.com/memory/showdoc.aspx?i=2989
About three years ago DDR2 memory first appeared on the desktop PC scene. It would be impossible to say it burst on the scene since it was introduced with the unimpressive Intel NetBurst processors. In that market DDR2 was more like a trickle since it was mainly a curiosity for a processor that was running a distant second place to the leading AMD Athlon chips, which were still powered by DDR memory.
DDR2 finally became the universal standard last May/June when AMD switched to DDR2 on their new AM2 platform and Intel introduced Core 2 Duo, the new CPU performance leader. Core 2 Duo resided on socket 775, which also was fed by DDR2. While it sometimes seems like centuries ago, it is worth remembering that Intel Core 2 Duo regained the CPU performance crown less than a year ago, and the two years prior to that all the fastest systems used AMD Athlon 64/X2/FX processors.
We compared performance of DDR2 on the new platforms in July of last year. AM2 provided better bandwidth with DDR2, but the better AM2 bandwidth did not translate into better performance. Since Core 2 Duo was faster at the same timings, it appeared the Intel Core 2 Duo architecture was not particularly bandwidth hungry and that it made very good use of the DDR2 bandwidth that was available with the chipset memory controller.
Since last May/June DDR2 has finally turned the market, and it has made some remarkable transformations along the way. The early 5-5-5 timings at the official DDR2-800 speed have since been replaced by several high performance memories capable of 3-3-3 timings at DDR2-800. The best memory at DDR2-1066 can now operate at 4-4-3 timings, and the fastest DDR2 is now around DDR2-1266 and still getting faster.
Perhaps even more remarkable, in the last year DDR2 memory prices have dropped to half of what they once were (sometimes more), and today DDR2 is often cheaper than the DDR memory it replaced. Compared to the very expensive prices at launch and into the holiday buying season we see DDR2 is now the memory price standard in the desktop computer market.
Fast forward a year and Intel is now launching their first chipsets to support DDR3 memory. In one of the sloppiest NDA launches in recent memory we already have P35 boards for sale since early May. The official chipset introduction is scheduled for May 21st and boards are "officially" launching into the retail channel on June 4th.
We can tell you that Intel does not really have an NDA, but they have been very aggressive in holding first tier manufacturers to a May 21st performance embargo and retail distribution on June 4th. Despite that, people around the world have been able to buy P35 boards from several retailers. We have retail boards we bought on the open market, which makes the 21st NDA a moot point in our opinion. Still, we value our relationship with both Intel and the major board makers, so this will not be a full P35 launch review. You will see that coming on May 21st.
What this review does address is the performance of the new DDR3 memory that is launched with P35. The new Intel P35 chipset, known as Bearlake during development, supports either DDR2 or DDR3 memory. This presented a perfect opportunity to look at the performance of both DDR3 and DDR2 on the new P35 chipset. We were also able to compare performance to a Gold Editors' Choice Intel P965 motherboard. The results of these comparisons provided interesting results about the capabilities of the new P35 memory controller. It also answered the question of whether you should care about DDR3 in any upcoming system purchase.
What is DDR3?
To provide compatibility and interchangeability for computer memory, the structure and form factor are controlled by a standards organization known as JEDEC. JEDEC specifies voltages, speeds, timings, communication protocols, bank addressing, and many other factors in the design and development of memory DIMMs. Taking a closer look at publications at www.jedec.org can provide insight into what DDR3 brings to the market and where it might go. Comparing DDR2 and DDR3 several interesting points stand out.
Official JEDEC Specifications
Please keep in mind that JEDEC specs are official. They are a starting point for enthusiast memory companies. However, since there was never a JEDEC standard for memory faster than DDR-400 then DDR memory running at faster speeds is really overclocked DDR-400. Similarly DDR2 memory faster than DDR2-800 is actually overclocked DDR2-800 since there is currently no official JEDEC spec for DDR2-1066.
DDR speeds ran to DDR-400, DDR2 has official specs from 400 to 800, and DDR3 will extend this from 800 to 1600 based on the current JEDEC specification. Initial DDR3 offerings will be 1066 and 1333 will quickly follow. The 1333 speed is important because it matches the 1333 bus speed of the new Intel processors. The 1333 processors can run any speed of DDR3 or DDR2 memory, but 800 and 1067 will be overlap speeds with DDR2. 1333 will be the first DDR3 speed to offer enhanced memory speeds to current and future processors.
Since DDR3 is designed to run at higher memory speeds the signal integrity of the memory module is now more important. DDR3 uses something called "fly-by" technology instead of the "T branches" seen on DDR2 modules. This means the address and control lines are a single path chaining from one DRAM to another, where DDR2 uses a T topology that branches on DDR2 modules. "Fly-by" takes away the mechanical line balancing and uses automatic signal time delay generated by the controller fixed at the memory system training. Each DDR3 DRAM chip has an automatic leveling circuit for calibration and to memorize the calibration data.
DDR3 also uses more internal banks - 8 instead of the 4 used by DDR2 - to further speed up the system. More internal banks allow advance prefetch to reduce access latency. This should become more apparent as the size of the DRAM increases in the future.
DDR3 further reduces the memory voltage. In the past few years we have moved from 2.5V with DDR to 1.8V with DDR2. DDR3 drops memory voltage to 1.5V, which is a 16% reduction from DDR2. There are also additional built-in power conservation features with DDR3 like partial refresh. This could be particularly important in mobile applications where battery power will no longer be needed just to refresh a portion of the DRAM not in active use. There is also a specification for an optional thermal sensor that could allow mobile engineers to save further power by providing minimum refresh cycles when the system is not in high performance mode.
There is even more to DDR3, but for most enthusiasts looking at a new desktop system DDR3 can provide higher official speeds, up to 1600MHz. The higher speeds are available at lower voltage, with 1.5V as the official specification. There are many features that will not make much difference in DDR3 performance until we begin to see even faster and higher capacity memory. The question, then, is whether DDR3 memory provides better performance for the computer enthusiast than current DDR2?
DDR3 Memory
DDR2 moved the "notch" to a different location so DDR2 could not be mounted in a DDR slot by accident, and vice versa. DDR3 provides a third notch configuration, designed to prevent mounting in older DDR and DDR2 slots.
The first DDR3 memory to show up in our labs is from Wintec, who will market the DDR3 kit under their AmpX brand name.
Corsair has also been at the forefront of DDR3 development and provided a Corsair 2 GB DDR3 kit for evaluation.
Both the Wintec and Corsair parts are rated at DDR3-1066 at 7-7-7-20 timings. Corsair also has a 1333 part that should be released in the next two weeks. We will follow up with that 1333 rated memory as soon as it is available.
DDR2 memory was also needed for the older P965 and new P35-based ASUS P5K Deluxe. Corsair Dominator DDR2-1111 was chosen for the wide range of available DDR2 memory speeds and the excellent timings available at DDR2-800 and DDR2-1067.
P35 Motherboards
Since the primary goal was to compare DDR2 and DDR3 performance it was important to find P35 motherboards that supported DDR2 and DDR3 in as similar a configuration as possible. ASUS will be marketing a pair of premium motherboards that differ only in the memory each motherboard supports.
The ASUS P5K3 Deluxe is powered by the Intel P35 chipset and fully supports DDR3 memory to an official DDR3-1333 speed.
The ASUS P5K Deluxe is based on the same P35 chipset but supports DDR2 memory. There are other minor differences in the two boards, but they are basically the same board supporting different memory types. This is exactly the configuration needed for our comparison.
For comparison to a current Intel chipset, the ASUS P5B Deluxe was used.
This excellent motherboard received the Gold Editors' Choice in the conclusion to our recent P965 motherboard roundup. It also supports a wide range of memory voltages and speeds which make it ideal for comparison testing to the P35 motherboards.
Link to Article: *www.anandtech.com/memory/showdoc.aspx?i=2989
About three years ago DDR2 memory first appeared on the desktop PC scene. It would be impossible to say it burst on the scene since it was introduced with the unimpressive Intel NetBurst processors. In that market DDR2 was more like a trickle since it was mainly a curiosity for a processor that was running a distant second place to the leading AMD Athlon chips, which were still powered by DDR memory.
DDR2 finally became the universal standard last May/June when AMD switched to DDR2 on their new AM2 platform and Intel introduced Core 2 Duo, the new CPU performance leader. Core 2 Duo resided on socket 775, which also was fed by DDR2. While it sometimes seems like centuries ago, it is worth remembering that Intel Core 2 Duo regained the CPU performance crown less than a year ago, and the two years prior to that all the fastest systems used AMD Athlon 64/X2/FX processors.
We compared performance of DDR2 on the new platforms in July of last year. AM2 provided better bandwidth with DDR2, but the better AM2 bandwidth did not translate into better performance. Since Core 2 Duo was faster at the same timings, it appeared the Intel Core 2 Duo architecture was not particularly bandwidth hungry and that it made very good use of the DDR2 bandwidth that was available with the chipset memory controller.
Since last May/June DDR2 has finally turned the market, and it has made some remarkable transformations along the way. The early 5-5-5 timings at the official DDR2-800 speed have since been replaced by several high performance memories capable of 3-3-3 timings at DDR2-800. The best memory at DDR2-1066 can now operate at 4-4-3 timings, and the fastest DDR2 is now around DDR2-1266 and still getting faster.
Perhaps even more remarkable, in the last year DDR2 memory prices have dropped to half of what they once were (sometimes more), and today DDR2 is often cheaper than the DDR memory it replaced. Compared to the very expensive prices at launch and into the holiday buying season we see DDR2 is now the memory price standard in the desktop computer market.
Fast forward a year and Intel is now launching their first chipsets to support DDR3 memory. In one of the sloppiest NDA launches in recent memory we already have P35 boards for sale since early May. The official chipset introduction is scheduled for May 21st and boards are "officially" launching into the retail channel on June 4th.
We can tell you that Intel does not really have an NDA, but they have been very aggressive in holding first tier manufacturers to a May 21st performance embargo and retail distribution on June 4th. Despite that, people around the world have been able to buy P35 boards from several retailers. We have retail boards we bought on the open market, which makes the 21st NDA a moot point in our opinion. Still, we value our relationship with both Intel and the major board makers, so this will not be a full P35 launch review. You will see that coming on May 21st.
What this review does address is the performance of the new DDR3 memory that is launched with P35. The new Intel P35 chipset, known as Bearlake during development, supports either DDR2 or DDR3 memory. This presented a perfect opportunity to look at the performance of both DDR3 and DDR2 on the new P35 chipset. We were also able to compare performance to a Gold Editors' Choice Intel P965 motherboard. The results of these comparisons provided interesting results about the capabilities of the new P35 memory controller. It also answered the question of whether you should care about DDR3 in any upcoming system purchase.
What is DDR3?
To provide compatibility and interchangeability for computer memory, the structure and form factor are controlled by a standards organization known as JEDEC. JEDEC specifies voltages, speeds, timings, communication protocols, bank addressing, and many other factors in the design and development of memory DIMMs. Taking a closer look at publications at www.jedec.org can provide insight into what DDR3 brings to the market and where it might go. Comparing DDR2 and DDR3 several interesting points stand out.
Official JEDEC Specifications
DDR2 // DDR3
Rated Speed 400-800 Mbps // 800-1600 Mbps
Vdd/Vddq 1.8V +/- 0.1V // 1.5V +/- 0.075V
Internal Banks 4 // 8
Termination Limited // All DQ signals
Topology Conventional T // Fly-by
Driver Control OCD Calibration // Self Calibration with ZQ
Thermal Sensor No // Yes (Optional)
Rated Speed 400-800 Mbps // 800-1600 Mbps
Vdd/Vddq 1.8V +/- 0.1V // 1.5V +/- 0.075V
Internal Banks 4 // 8
Termination Limited // All DQ signals
Topology Conventional T // Fly-by
Driver Control OCD Calibration // Self Calibration with ZQ
Thermal Sensor No // Yes (Optional)
Please keep in mind that JEDEC specs are official. They are a starting point for enthusiast memory companies. However, since there was never a JEDEC standard for memory faster than DDR-400 then DDR memory running at faster speeds is really overclocked DDR-400. Similarly DDR2 memory faster than DDR2-800 is actually overclocked DDR2-800 since there is currently no official JEDEC spec for DDR2-1066.
DDR speeds ran to DDR-400, DDR2 has official specs from 400 to 800, and DDR3 will extend this from 800 to 1600 based on the current JEDEC specification. Initial DDR3 offerings will be 1066 and 1333 will quickly follow. The 1333 speed is important because it matches the 1333 bus speed of the new Intel processors. The 1333 processors can run any speed of DDR3 or DDR2 memory, but 800 and 1067 will be overlap speeds with DDR2. 1333 will be the first DDR3 speed to offer enhanced memory speeds to current and future processors.
Since DDR3 is designed to run at higher memory speeds the signal integrity of the memory module is now more important. DDR3 uses something called "fly-by" technology instead of the "T branches" seen on DDR2 modules. This means the address and control lines are a single path chaining from one DRAM to another, where DDR2 uses a T topology that branches on DDR2 modules. "Fly-by" takes away the mechanical line balancing and uses automatic signal time delay generated by the controller fixed at the memory system training. Each DDR3 DRAM chip has an automatic leveling circuit for calibration and to memorize the calibration data.
DDR3 also uses more internal banks - 8 instead of the 4 used by DDR2 - to further speed up the system. More internal banks allow advance prefetch to reduce access latency. This should become more apparent as the size of the DRAM increases in the future.
DDR3 further reduces the memory voltage. In the past few years we have moved from 2.5V with DDR to 1.8V with DDR2. DDR3 drops memory voltage to 1.5V, which is a 16% reduction from DDR2. There are also additional built-in power conservation features with DDR3 like partial refresh. This could be particularly important in mobile applications where battery power will no longer be needed just to refresh a portion of the DRAM not in active use. There is also a specification for an optional thermal sensor that could allow mobile engineers to save further power by providing minimum refresh cycles when the system is not in high performance mode.
There is even more to DDR3, but for most enthusiasts looking at a new desktop system DDR3 can provide higher official speeds, up to 1600MHz. The higher speeds are available at lower voltage, with 1.5V as the official specification. There are many features that will not make much difference in DDR3 performance until we begin to see even faster and higher capacity memory. The question, then, is whether DDR3 memory provides better performance for the computer enthusiast than current DDR2?
DDR3 Memory
DDR2 moved the "notch" to a different location so DDR2 could not be mounted in a DDR slot by accident, and vice versa. DDR3 provides a third notch configuration, designed to prevent mounting in older DDR and DDR2 slots.
*images.anandtech.com/reviews/memory/ddr3/p35-ddr2-vs-ddr3/ddr3-ddr2.jpg
<Click here if you can't see the Image>
The first DDR3 memory to show up in our labs is from Wintec, who will market the DDR3 kit under their AmpX brand name.
*images.anandtech.com/reviews/memory/ddr3/p35-ddr2-vs-ddr3/wintec.jpg
<Clink here if you can't see the Image>
Corsair has also been at the forefront of DDR3 development and provided a Corsair 2 GB DDR3 kit for evaluation.
*images.anandtech.com/reviews/memory/ddr3/p35-ddr2-vs-ddr3/corsair.jpg
<Click here if you can't see the Image>
Both the Wintec and Corsair parts are rated at DDR3-1066 at 7-7-7-20 timings. Corsair also has a 1333 part that should be released in the next two weeks. We will follow up with that 1333 rated memory as soon as it is available.
*images.anandtech.com/reviews/memory/ddr3/p35-ddr2-vs-ddr3/dominator.jpg
<Click here if you can't see the Image>
DDR2 memory was also needed for the older P965 and new P35-based ASUS P5K Deluxe. Corsair Dominator DDR2-1111 was chosen for the wide range of available DDR2 memory speeds and the excellent timings available at DDR2-800 and DDR2-1067.
P35 Motherboards
Since the primary goal was to compare DDR2 and DDR3 performance it was important to find P35 motherboards that supported DDR2 and DDR3 in as similar a configuration as possible. ASUS will be marketing a pair of premium motherboards that differ only in the memory each motherboard supports.
*images.anandtech.com/reviews/memory/ddr3/p35-ddr2-vs-ddr3/p5k3_sml.jpg
<Click here if you can't see the Image>
The ASUS P5K3 Deluxe is powered by the Intel P35 chipset and fully supports DDR3 memory to an official DDR3-1333 speed.
*images.anandtech.com/reviews/memory/ddr3/p35-ddr2-vs-ddr3/p5b_sml.jpg
<Click here if you can't see the Image>
The ASUS P5K Deluxe is based on the same P35 chipset but supports DDR2 memory. There are other minor differences in the two boards, but they are basically the same board supporting different memory types. This is exactly the configuration needed for our comparison.
For comparison to a current Intel chipset, the ASUS P5B Deluxe was used.
*images.anandtech.com/reviews/memory/ddr3/p35-ddr2-vs-ddr3/p5k_sml.jpg
<Click here if you can't see the Image>
This excellent motherboard received the Gold Editors' Choice in the conclusion to our recent P965 motherboard roundup. It also supports a wide range of memory voltages and speeds which make it ideal for comparison testing to the P35 motherboards.
