We'll start the analysis of the new chipset family with its top representative. It's not yet available in the market and will debut only in Q3 together with the second wave of the new chipsets. Note that top products used to be marked with an increased index number (i915 - i925). And now the top product is marked with the X prefix - Intel uses it to designate any general improvements (not only in chipsets, but in processors, graphics cards, etc). The following block diagram shows the key characteristics of the X38:
Let's enumerate the key functions of its Northbridge:
Support for new Celeron and Pentium processors as well as all Core 2 models (Duo/Quad/Extreme) with 800/1066 MHz FSB, including future models with 1333 MHz FSB
Dual-channel DDR2-533/667/800 or DDR3-800/1066/1333 memory controller, up to 4 DIMM modules with the total size of up to 8 GB (with ECC), Fast Memory Access and Flex Memory technologies
Twin x16 PCI Express 2.0 slots
DMI bus (~2 GB/s bandwidth) to the new ICH9/R/DH/DO Southbridge.
We can see well that all key characteristics of the chipset have been modified. Let's analyze all innovations one by one.
CPU support. It must be noted here that all 3-series chipsets officially don't support Celeron D, Pentium 4, and Pentium D processors (as well as their Extreme Edition modifications). The lack of support is caused not by the modified characteristics of the processor bus, but by the new motherboard standard - FMB (to be more exact, by VRM), which supports future 45 nm processors, instead of 90 nm (and older) models. There is no direct connection between this chipset and its power supply subsystem, of course. But manufacturers almost always follow Intel design standards. So it's highly improbable that we'll see many Intel 3x models with support for "pre-Core 2" processors. To say nothing of motherboards supporting both Prescott and Penryn.
What concerns the Core 2 support, X38 does it perfectly: this chipset will officially support all existing and future models of Core 2 Duo, Core 2 Quad and Core 2 Extreme processors (including quad-core modifications) with a 1333 MHz bus. All low-end families of the new processors (Celeron 400 and Pentium E2000) will work with the X38. But the top chipset will not support Celeron 400 for marketing reasons.
Memory support. Features of the DDR2 controller have not changed in all new chipsets (no alterations are in view here, all features described in the specifications are already implemented). But motherboards based on Intel 3x will work with DDR3 memory as well. Peculiarities and theoretical performance of the new memory type are already analyzed in our review. This article will touch upon practical aspects only. Here comes the first traditional question - is simultaneous support for DDR2 and DDR3 possible? The situation is not different from DDR and DDR2: Intel does not officially test such combinations, but motherboard manufacturers can do it on their own. Our constant readers have surely heard about several models of combo motherboards. Besides, our today's tests were run on one of such models (but we'll hardly see X38-based combo models). DDR2 and DDR3 memory modules cannot work simultaneously, of course: the motherboard will initiate memory modules of only one type.
DDR3 is very good: it features lower heat release (memory voltage is reduced, so that even DDR3-1066 will dissipate less heat than DDR2-800); a different location of the key notch will not let you mix up DDR2 and DDR3 memory slots on combo motherboards. As you already know, DDR3 is supposed to work at up to 800(1600) MHz. X38 will support one of the fastest modifications - DDR3-1333. But the situation with availability and timings of memory at the time of Intel 3x debut is not very good. DDR3 modules are not available in the market on a mass scale. Even elite manufacturers (such as Corsair) take advantage of this situation and sell modules with mediocre characteristics at fabulous prices. Rational readers are recommended to wait until their prices go down and their characteristics are improved. As for now, analysts forecast that DDR3 will take up 50% of the market only by 2009. It will hardly capture 10% by the end of 2007. And in the practical part of the article we'll see what we are offered at such a high price.
PCI Express 2.0. Intel strikes a pre-emptive blow here. It has finally designed a chipset with support for two full-speed PCI Express x16 interfaces, which have been available in top products from competitors for a long time already (this configuration does not have a noticeable advantage in most cases, but principles are more important), and has implemented a host controller of the second version. PCI Express 2.0 still allows to use old graphics cards, because it has the same slots, compatible both ways. The new features of PCI Express 2.0 will hardly be very interesting for the graphics interface, except for two points. Firstly, performance of each PCI Express lane is doubled, so a single lane (PCIEx1) has a bandwidth of 500 MB/s each way. The total bandwidth of a 16-lane PCIEx16 interface is 16 GB/s. I repeat, there will be no practical advantage of this system in the nearest future.
Secondly, the power applied to the bus is also doubled: PCIEx16 slot of the first version provided up to 75 W, now a graphics card can get 150 W. (I wonder how these additional Watts get into the bus - will X38-based motherboards have a special additional power connector?) However, top accelerators neglect the power supply from PCIEx16. You can use one of the two on-board power connectors at best. It's similar to the situation with PCI Express graphics cards with on-board power connectors (75 W from the bus turned out to be insufficient) that appeared with the launch of i915/925-based motherboards. However, we should thank SLI/CrossFire for that: top graphics cards are first of all designed for tandem configurations - while a single graphics card may theoretically work on the power from the bus, the second graphics card without an on-board power connector will not startup. What concerns joining graphics cards on Intel X38, everything is the same: CrossFire is officially supported. SLI is not supported and won't be in the nearest future.
X38 will come with a new south bridge of the ICH9 family. Functionality of this family will be examined below.
Intel P35 Express
This chipset belongs to the Performance group. The workhorse of the new series has the following architecture:
Let's enumerate the key functions of its Northbridge:
Support for new Celeron and Pentium processors as well as all Core 2 models (Duo/Quad/Extreme) with 800/1066 MHz FSB, including future models with 1333 MHz FSB
Dual-channel DDR2-533/667/800 or DDR3-800/1066/1333 memory controller, up to 4 DIMM modules with the total size of up to 8 GB (with ECC), Fast Memory Access and Flex Memory technologies
Twin x16 PCI Express 2.0 slots
DMI bus (~2 GB/s bandwidth) to the new ICH9/R/DH/DO Southbridge.
We can see well that all key characteristics of the chipset have been modified. Let's analyze all innovations one by one.
CPU support. It must be noted here that all 3-series chipsets officially don't support Celeron D, Pentium 4, and Pentium D processors (as well as their Extreme Edition modifications). The lack of support is caused not by the modified characteristics of the processor bus, but by the new motherboard standard - FMB (to be more exact, by VRM), which supports future 45 nm processors, instead of 90 nm (and older) models. There is no direct connection between this chipset and its power supply subsystem, of course. But manufacturers almost always follow Intel design standards. So it's highly improbable that we'll see many Intel 3x models with support for "pre-Core 2" processors. To say nothing of motherboards supporting both Prescott and Penryn.
What concerns the Core 2 support, X38 does it perfectly: this chipset will officially support all existing and future models of Core 2 Duo, Core 2 Quad and Core 2 Extreme processors (including quad-core modifications) with a 1333 MHz bus. All low-end families of the new processors (Celeron 400 and Pentium E2000) will work with the X38. But the top chipset will not support Celeron 400 for marketing reasons.
Memory support. Features of the DDR2 controller have not changed in all new chipsets (no alterations are in view here, all features described in the specifications are already implemented). But motherboards based on Intel 3x will work with DDR3 memory as well. Peculiarities and theoretical performance of the new memory type are already analyzed in our review. This article will touch upon practical aspects only. Here comes the first traditional question - is simultaneous support for DDR2 and DDR3 possible? The situation is not different from DDR and DDR2: Intel does not officially test such combinations, but motherboard manufacturers can do it on their own. Our constant readers have surely heard about several models of combo motherboards. Besides, our today's tests were run on one of such models (but we'll hardly see X38-based combo models). DDR2 and DDR3 memory modules cannot work simultaneously, of course: the motherboard will initiate memory modules of only one type.
DDR3 is very good: it features lower heat release (memory voltage is reduced, so that even DDR3-1066 will dissipate less heat than DDR2-800); a different location of the key notch will not let you mix up DDR2 and DDR3 memory slots on combo motherboards. As you already know, DDR3 is supposed to work at up to 800(1600) MHz. X38 will support one of the fastest modifications - DDR3-1333. But the situation with availability and timings of memory at the time of Intel 3x debut is not very good. DDR3 modules are not available in the market on a mass scale. Even elite manufacturers (such as Corsair) take advantage of this situation and sell modules with mediocre characteristics at fabulous prices. Rational readers are recommended to wait until their prices go down and their characteristics are improved. As for now, analysts forecast that DDR3 will take up 50% of the market only by 2009. It will hardly capture 10% by the end of 2007. And in the practical part of the article we'll see what we are offered at such a high price.
PCI Express 2.0. Intel strikes a pre-emptive blow here. It has finally designed a chipset with support for two full-speed PCI Express x16 interfaces, which have been available in top products from competitors for a long time already (this configuration does not have a noticeable advantage in most cases, but principles are more important), and has implemented a host controller of the second version. PCI Express 2.0 still allows to use old graphics cards, because it has the same slots, compatible both ways. The new features of PCI Express 2.0 will hardly be very interesting for the graphics interface, except for two points. Firstly, performance of each PCI Express lane is doubled, so a single lane (PCIEx1) has a bandwidth of 500 MB/s each way. The total bandwidth of a 16-lane PCIEx16 interface is 16 GB/s. I repeat, there will be no practical advantage of this system in the nearest future.
Secondly, the power applied to the bus is also doubled: PCIEx16 slot of the first version provided up to 75 W, now a graphics card can get 150 W. (I wonder how these additional Watts get into the bus - will X38-based motherboards have a special additional power connector?) However, top accelerators neglect the power supply from PCIEx16. You can use one of the two on-board power connectors at best. It's similar to the situation with PCI Express graphics cards with on-board power connectors (75 W from the bus turned out to be insufficient) that appeared with the launch of i915/925-based motherboards. However, we should thank SLI/CrossFire for that: top graphics cards are first of all designed for tandem configurations - while a single graphics card may theoretically work on the power from the bus, the second graphics card without an on-board power connector will not startup. What concerns joining graphics cards on Intel X38, everything is the same: CrossFire is officially supported. SLI is not supported and won't be in the nearest future.
X38 will come with a new south bridge of the ICH9 family. Functionality of this family will be examined below.
Intel P35 Express
This chipset belongs to the Performance group. The workhorse of the new series has the following architecture:
No comments:
Post a Comment