Is XMP on all Intel CPUs?
Is XMP on all Intel CPUs?
Pinhedd :
Hi,
there seems to be a little bit of confusion here.
XMP is not a CPU feature, it is a firmware feature. In particular, it is a feature that allows the firmware to interpret sections of the DRAM SPD beyond the standard JEDEC configuration region and use the data stored within that region to calculate and configure non-standard performance profiles.
By default, x86 firmware will always configure the SDRAM according to JEDEC specifications stored in the SPD (the DIMM's parameter ROM) and the memory controller's parameters. This ensures maximum probability of baseline operation. When JEDEC specifications are adhered to, the probability of the memory not operating at all is minimized; when JEDEC specifications are violated, the probability that the memory will not work, or will not work consistently, rises dramatically.
The capabilities of XMP are limited by the memory controller's capabilities. For example, if the memory controller is physically incapable of being programmed to generate the clock frequency specified by the XMP profile then XMP is worthless. Furthermore, even if the memory controller is capable of being programmed to generate the necessary clock rate there's no guarantee that the memory controller will be able to train the signals, keep jitter in check, properly compensate for signal skew, centre the eye, etc... there are a huge number of things that can go wrong and it only takes one to render everything inoperable.
In addition to being a technical feature, XMP is also an Intel trademark. DIMM vendors that wish to use the XMP trademark must submit their designs for testing and validation by Intel. Intel does perform significant testing to ensure that XMP branded memory is going to work as well as possible when operating outside of JEDEC specifications; however, Intel does not provide a guarantee like they do when the memory is configured within Intel's specifications (which are a platform specific extension of JEDEC's). With that said, many users often take memory even further, often by installing multiple identical sets of DIMMs. Whereas a single set of DIMM's (one DIMM per channel) are tested to work nicely with the XMP profile alone, two sets installed together (two DIMMs per channel) may require additional tweaking above and beyond simply enabling XMP.
So i got a question. I got a MSI H97 gaming 3 Mobo, I5 - 4460 CPU, 4x4 GB Gskill sniper 2400 mhz. I saw the XMP option in the bios and enable it, but my pc just show as 1600 mhz. So if the XMP depend on firmware, why it isn't working ?
Kurodax :
Pinhedd :
Hi,
there seems to be a little bit of confusion here.
XMP is not a CPU feature, it is a firmware feature. In particular, it is a feature that allows the firmware to interpret sections of the DRAM SPD beyond the standard JEDEC configuration region and use the data stored within that region to calculate and configure non-standard performance profiles.
By default, x86 firmware will always configure the SDRAM according to JEDEC specifications stored in the SPD (the DIMM's parameter ROM) and the memory controller's parameters. This ensures maximum probability of baseline operation. When JEDEC specifications are adhered to, the probability of the memory not operating at all is minimized; when JEDEC specifications are violated, the probability that the memory will not work, or will not work consistently, rises dramatically.
The capabilities of XMP are limited by the memory controller's capabilities. For example, if the memory controller is physically incapable of being programmed to generate the clock frequency specified by the XMP profile then XMP is worthless. Furthermore, even if the memory controller is capable of being programmed to generate the necessary clock rate there's no guarantee that the memory controller will be able to train the signals, keep jitter in check, properly compensate for signal skew, centre the eye, etc... there are a huge number of things that can go wrong and it only takes one to render everything inoperable.
In addition to being a technical feature, XMP is also an Intel trademark. DIMM vendors that wish to use the XMP trademark must submit their designs for testing and validation by Intel. Intel does perform significant testing to ensure that XMP branded memory is going to work as well as possible when operating outside of JEDEC specifications; however, Intel does not provide a guarantee like they do when the memory is configured within Intel's specifications (which are a platform specific extension of JEDEC's). With that said, many users often take memory even further, often by installing multiple identical sets of DIMMs. Whereas a single set of DIMM's (one DIMM per channel) are tested to work nicely with the XMP profile alone, two sets installed together (two DIMMs per channel) may require additional tweaking above and beyond simply enabling XMP.
So i got a question. I got a MSI H97 gaming 3 Mobo, I5 - 4460 CPU, 4x4 GB Gskill sniper 2400 mhz. I saw the XMP option in the bios and enable it, but my pc just show as 1600 mhz. So if the XMP depend on firmware, why it isn't working ?
Hi,
Many DIMMs that feature XMP profiles often include more than one profile. Typically, only the profile for the highest data rate is advertised. Your DIMM may contain an XMP profile for DDR3-1600 as well as DDR3-2400. This enables customers whose motherboards may be incapable of operating at the advertised data rate to still benefit from the XMP feature. In almost all cases, XMP-1600 will have tighter timings than the JEDEC DDR3-1600 profile that would be configured automatically if XMP-2400 fails. Please make sure that you have selected the appropriate XMP profile in the BIOS/UEFI setup. In most cases this will be the numerically largest XMP profile number.
Initial XMP doesn't cover every DDR3 variant as previously noted; it's specifically designed for DRAM 1600 and higher. Usually, the SPD of these DRAMs includes two XMP profiles, usually matching the same data rate—such as 2400—where profile 1 follows the official spec, and profile 2 is often an enthusiast setting (the main distinction being a tighter command rate, like 1T or 1N compared to the standard 2T or 2N). The T and N labels are interchangeable and mostly just indicate the manufacturer's preference (AMD tends to use N, Intel uses T). SPD also contains various recommended configurations for lower data rates, such as 1600 and 1333, which can be applied based on the motherboard's default boot-up speed or as a manual reference.
Tradesman1 explained the differences in XMP support for DDR3, noting it applies mainly to DRAM 1600 and above. He mentioned that most DRAMs have two XMP profiles, usually matching the same data rate, with one being the official spec and another an enthusiast version. He also pointed out that the SPD often includes settings for lower data rates and can serve as a guide for manual configuration.
In the upper image (CPU-Z) it displays the XMP profile set to 2400, but the motherboard can't handle that because it's an H97. I would attempt 1600 with settings 9-9-9-24 and 1.5.