same time, but only one port can be used at a time. ATI ATI Radeon Xpress 200 ATI Radeon Xpress 1250 ATI CrossFire Xpress 3200 Nvidia nForce4 Ultra nForce4 SLI XE nForce4 SLI; nForce4 SLI X16 nForce 570 SLI nForce 590 SLI nForce 610i nForce 620i nForce 630i nForce 650i Ultra nForce 650i SLI nForce 680i LT SLI nForce 680i SLI nForce 730i nForce 740i SLI nForce 750i SLI nForce 760i SLI nForce 780i SLI nForce 790i SLI GeForce 9300 GeForce 9400 Improvements in heat dissipation The force from the load plate ensures that the processor is completely level, giving the CPU's upper surface optimal contact with the heat sink or cold-water block fixed onto the top of the CPU to carry away the heat generated by the CPU. This socket also introduces a new method of connecting the heat dissipation interface to the chip surface and motherboard. With LGA 775, the heat dissipation interface is connected directly to the motherboard on four points, compared with the two connections of the Socket 370 and the "clamshell" four-point connection of the Socket 478. This was done to avoid the reputed danger of the heat sinks/fans of pre-built computers falling off in transit. LGA 775 was announced to have better heat dissipation properties than the Socket 478 it was designed to replace, but the Prescott core CPUs (in their early incarnations) ran much hotter than the previous Northwood-core Pentium 4 CPUs, and this initially neutralized the benefits of better heat transfer. However, the later Core 2 processors run at much lower temperatures than the Prescott CPUs they replaced. Processors with lower TDP and clock speeds only used Thermal Interface Compound in between the die and the integrated heat spreader (IHS), while processors with higher TDP and clock speeds have the die soldered directly to the IHS, allowing for better heat transfer between the CPU and the integrated heat spreader. LGA 775 mechanical load limits All LGA 775 processors have the following mechanical maximum load limits which should not be exceeded during heat sink assembly, shipping conditions, or standard use. Load above those limits could crack the processor die and make it unusable. The transition to the LGA packaging has lowered those load limits, which are smaller than the load limits of Socket 478 processors but they are bigger than Socket 370, Socket 423 and Socket A processors, which were fragile. They are