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Processors (Intel® Core™, Intel® Xeon®, etc); processor utilities and programs (Intel® Processor Identification Utility, Intel® Extreme Tuning Utility, Intel® Easy Streaming Wizard, etc.)
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Does clearing the IA32_MTRR_DEF_TYPE.E flag disable the System-Management Range Registers?

HadiBrais
New Contributor III
353 Views

The Software Developer's Manual Volume 3 (Order Number: 325384-072US) states in Section 11.11.2.1 that the E flag (bit 11) of the IA32_MTRR_DEF_TYPE MSR register can be used to enable or disable all MTRRs. It's clear that this flag, when set to zero, disables all variable-range and fixed-range MTRRs.

Section 11.11.2.4 discusses another set of MTRRs called the system-management range registers (SMRR). I couldn't find a clear statement in the manual regarding whether the flag IA32_MTRR_DEF_TYPE[11] disables the SMRR, in addition to the variable-range and fixed-range MTRRs. Are there any MTRRs that are not disabled by clearing IA32_MTRR_DEF_TYPE[11]? Is the answer dependent on the processor?

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3 Replies
n_scott_pearson
Super User Retired Employee
326 Views

This is not a question to be answered here. You should ask it in the Intel Developer Zone forum.

...S

HadiBrais
New Contributor III
322 Views

Well, none of the forums there seem to be more suitable for my question.

The question is really about Intel processors, so I think it's at least somewhat suitable here.

n_scott_pearson
Super User Retired Employee
319 Views

No, this is not the site for questions related to registers and programming. That's specifically what the Developer Zone is for.

...S

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