that the chipset disconnects Front Side Bus after receiving request generated by the processor. Majority of K7 chipsets support this, but on older motherboards this is often not enabled by default due to problems with this feature. Those problems are usually in form of sound crackles, lowered HDD performance, PCI problems etc. For proper functionality of this feature, you need a chipset-enabled FSB disconnect after Halt special system bus cycle (set by BIOS, otherwise use WPCREDIT/WPCRSET). Higher divisors result in lower frequency what turns in somewhat lower temperature and lower power consumption. On the other hand, those higher divisors tend to cause problems described above and sometimes even to systems hangs. The result of enabling C1/Halt Bus Disconnect can be as much as 15 degrees Celsius temperature decrease. Different divisors have somewhat lower effect, the difference between 8 and 512 can be 5 degrees at most.
  • Stop Grant Disconnect Clock Divisor - this is the same as for Halt Disconnect Clock Divisor with the difference that this one sets frequency divisor for C2/Stop Grant power saving mode. The effect of power requirements reduction is the same as in case of C1/Halt mode, but there are few differences. First - chipset has to be set to disconnect FSB upon receiving Stop Grant request, not Halt request. On many chipsets, there are separate bits for Halt and for Stop Grant, so be sure to set the right one. Second - you do not need any program to enter to C2 Stop Grant state because Windows 2000/XP have already integrated mechanism that does this, provided that C2 state is defined and allowed to be used in the ACPI table.
  • Full Ramp - determines a max possible delay when ramping up/down the internal CPU clock. No information is currently available for this setting, so it's best to leave it default.
  • Ramp Delays (Clock Change Timings) - these settings affect time between clock changes inside the CPU while entering to/from C1/Halt or C2/Stop Grant states, provided that the Halt/Stop Grant Bus Disconnect is enabled in the chipset settings. Faster settings mean lower latencies and therefore higher performance and better resistance to problems with sound cards, HDD performance etc. But on the other hand, faster settings impose higher requirements on internal clock generator. If you experience problems with stability, use the slower settings (e.g., 8 or 16 for all fields).
  • Enable Stop Grant APIC Bus Disconnect - controls whether the CPU should reject any APIC Bus messages while being in C2/Stop Grant state. If you have problems with this low-power mode, try disabling this option.
    NOTE: APIC Bus Disconnect has nothing to do with the AMD S2K Bus Disconnect feature that is enabled separately in the chipset configuration registers settings and is beyond the scope of RMClock utility.

    P-State Transitions Settings

    The utility must be restarted for these settings to have an effect.

    Remember these settings - makes the utility apply the low power modes settings every time the utility starts (or when the system is restored from Standby/Hibernate states).

    Advanced page (AMD K8 processors)

    Power Management Settings (Per ACPI State)

    Clock Power/Timings

    P-State Transitions Settings

    You must restart the utility for these settings to have an effect.

    Remember these settings - makes the utility apply the user-defined ACPI power management and clock power/timing settings every time the utility starts (or when the system is restored from Standby/Hibernate states).

    Advanced page (Intel Centrino platform / Processor settings)

    Automatic Thermal Protection

    Sets the preferred way of automatic thermal protection (Thermal Monitor 1 or Thermal Monitor 2, if available).
    NOTE: the CPU is operating out of spec when both TM1 and TM2 are disabled.

    Thermal Monitor 2 Target

    Defines the FID and VID values the CPU will transition to on activation of the Thermal Monitor 2 feature, provided the CPU supports TM2 and TM2 target programming.

    Enhanced Intel SpeedStep (EIST) Settings

    Enhanced Low Power States

    These settings allow to enable or disable any of the given enhanced C-states (C1E, C2E, C3E, C4E and Hard C4E) available on Intel Core Solo/Core Duo processors. When an Enhanced C-state is enabled, the CPU is automatically put into the lowest frequency/voltage mode when it enters a given C-state.

    Advanced page (Intel Centrino platform / Platform settings)

    Remember these settings - makes the utility apply the user-defined Automatic Thermal Protection, Enhanced SpeedStep and Centrino chipset settings every time the utility starts (or when the system is restored from Standby/Hibernate states).

    Advanced page (Intel Pentium 4 and Xeon processors)

    Automatic Thermal Protection

    Sets the preferred way of automatic thermal protection (Thermal Monitor 1 or Thermal Monitor 2, if available).
    NOTE: the CPU is operating out of spec when both TM1 and TM2 are disabled.

    Thermal Monitor 2 Target

    Defines the FID and VID values the CPU will transition to on activation of the Thermal Monitor 2 feature, provided the CPU supports TM2 and TM2 target programming.

    Enhanced Intel SpeedStep (DBS) Settings

    Misc Settings

    Remember these settings - makes the utility apply the user-defined Automatic Thermal Protection, Enhanced SpeedStep and misc settings every time the utility starts (or when the system is restored from Standby/Hibernate states).

    Advanced page (Transmeta processors)

    Power Source Select

    Displays current power source (upon Refresh button), and allows to select the power source you want to view/modify the settings for.

    LongRun Status and Control

    LongRun Advanced Thermal Management

    ATM Level - selects the processor power reduction target. LongRun will attempt to meet or exceed the power reduction level specified in this field by lowering the processor frequency and voltage. This setting has priority to reduce the processor frequency below that which is selected in the LongRun Bounds. This setting will never have the effect of increasing the processor freqeuency and voltage.

    LongRun Table Interface Data

    Lists available processor's LongRun levels, with detailed info on each of them.

    Remember these settings - makes the utility apply the user-defined LongRun and LongRun ATM settings every time the utility starts, when the system is restored from Standby/Hibernate states and when the power source changes.

    Tray icon menu

    Main tray icon menu

    CPU frequency indicator menu

    CPU load indicator menu

    Command-line parameters

    Beginning with version 1.6, RMClock can be launched with command-line parameters. Some of these commands work only at the first program startup (diagnostic or debug commands), others require that the utility is already running (control commands). Currently implemented command-line parameters include:

    Miscellaneous options


    CPU Power Management drivers/software

    RMClock is compatible with AMD Cool`n'Quiet(tm) / PowerNow!(tm), Enhanced Intel(R) SpeedStep(tm) and Transmeta LongRun(tm) software, provided it is not currently active. There's no need to uninstall existing processor driver, moreover, beginning with version 2.0, RMClock automatically disables the driver's power management by selecting its own power scheme at the program start-up. Current power scheme is automatically restored upon exiting RMClock utilty.

    Performance analyzing software

    Since RMClock relies upon CPU-specific performance monitoring counters (PMC) to determine the CPU usage level, compatibility issues are possible with application performance analyzing applications like Intel VTune or AMD CodeAnalyst, which use the same counters to monitor processor-specific performance events. Therefore, you should quit RMClock utility before using this kind of software.

    Benchmarking software

    As with any power management software, the performance/power management features of RMClock should be disabled before running any benchmarking software (e.g., your profile should be set to "No Management", or one of the fixed performance state profiles). Otherwise, you may get incorrect benchmark results.

    Frequently Asked Questions

    Q: How do I quickly set up RightMark CPU Clock Utility so that it performs automatic management of my CPU performance/power?

    A: Beginning with version 2.05, the easiest way to set up your new or updated RMClock installation is to go to the Management and Profiles page and click the Defaults button. Confirming this action will set up all four basic profiles with their default values, apply the management settings defaults and set the "Performance on Demand" profile as your current profile. Your CPU must support the required power management features, otherwise, this option will be disabled.
    NOTE: Your system might lock up as a result of this action if your hardware isn't properly configured to support the CPU power management features (e.g., for AMD Athlon 64 systems, if you have a motherboard not certified for AMD Cool`n'Quiet or have disabled Cool`n'Quiet support in the BIOS settings).

    Q: How do I uninstall RightMark CPU Clock Utility?

    A: Uninstalling RMClock is really easy. It is enough just to exit the utility if it is currently running and completely delete the folder you have installed it into. To ensure a complete clean-up of the program registry settings, you can apply the RMClock_WipeOut.reg file found in RMClock folder before deleting.

    Q: Why can't I run RMClock as a regular user?

    A: RMClock is a low-level system utility that requires privileged access to the CPU hardware, which can be done only via a kernel-mode driver (RTCore32/64.sys, which is dynamically extracted and installed at runtime). Administrative rights are required to install and load this driver, therefore, current versions of the utility can be run only by the users with administrative privileges.

    Q: CPU voltage indicated by RMClock greatly differs from the voltage reported by my vendor-supplied monitoring software. What's wrong?

    A: Nothing. RMClock reports the CPU VID, i.e., just the requested CPU voltage level. It is up to the motherboard logic to decide whether this request should be handled or ignored. Most motherboards designed to properly support processor's power-saving features (e.g., AMD Cool`n'Quiet(tm) technology) should adjust the real CPU voltage so that it's close to the requested VID level. Other models may apply some extra over-voltage (e.g., +0.1 or +0.2V), which is useful for overclocking. Finally, there are many motherboard models that can be set up (via BIOS settings) to supply constant voltage to the CPU, which is far from being good for achieving significant power saving.

    Q: Why can't I set CPU voltage above 1.55V (or even 1.45V), or below 1.1V on my Athlon 64? BIOS setup offers the voltages from 0.8V up to 1.7V. Is there a way to unlock these "hidden" voltages?

    A: RMClock manipulates with VID and not directly with the CPU voltage. Maximal VID value you can set is dictated by the CPU itself (as indicated in the "Maximal VID" field of the General page), as well as the Minimal VID. 1.55V is the absolute maximum VID for all Athlon 64 processors family; usually, maximal VID is even lower (e.g., 1.45V). There's no way to set current VID value higher than the maximal, as the CPU will choose maximal value instead (the same is true for FID, the bus clock multiplier). It is also impossible to program a VID being lower than the Minimal VID reported by the CPU. The voltage level you adjust in the BIOS is set in entirely different way, via direct manipulation with the CPU VRM and not involving VID changes. Please also note that the voltages you set manually in the BIOS setup cause the motherboard logic to ignore VID change requests, thus greatly diminishing power saving features of the AMD Cool`n'Quiet(tm) technology.

    Q: In the Advanced page I can adjust the Halt and Stop Grant bus disconnect divisors for my Athlon XP, but they don't seem to have any effect. What's wrong?

    A: Nothing. These settings only affect the CPU internal clock divisors. They do not enable bus disconnect for a Halt and/or Stop Grant state, which must be done in a chipset-specific way. No support for this and numerous chipsets series is ever planned.

    Q: In the Advanced page I see various ACPI states for my Athlon 64. What state should I choose?

    A: You don't have to choose anything particular. This is just a selector that allows changing the settings of a given ACPI state. It does not enable or even put the CPU into this particular state.

    Q: In the Advanced page of RMClock I see really a lot of settings for my Athlon 64. What are these all settings for? What settings should I choose?

    A: These are advanced settings that should not be changed without a good knowledge. In fact, they should be left alone if you don't experience any problems with you system. However, it is safe to load one of the predefined sets of defaults by using the corresponding buttons. If you're interested in these settings in detail, please look through Chapter 9 of the public AMD document "BIOS and Kernel Developer's Guide for AMD Athlon(TM) 64 and AMD Opteron(TM) Processors", order #26094.

    Q: My Athlon 64 system locks up when I enable automatic PST management in RMClock, what to do?

    A: Before you start, please be sure to disable the power management features of the AMD processor driver by setting your current power scheme (in Windows control panel) to "Home/Office Desk" or "Always On". This step is not necessary if you are using RMClock version 2.0 or higher and haven't disabled Windows power management handling in your profile settings.

    First, make sure you have selected relatively safe minimal and maximal FID/VID settings in your current profile settings (the ones selected by clicking Defaults button should be completely safe to begin with, provided your CPU is not overclocked).

    Second, ensure that your CPU is properly setup to support FID/VID change requests. This should be done by a BIOS during POST, however, if your motherboard is not certified by AMD for Cool`n'Quiet(tm) technology support, it might be necessary to do this manually. Most efficiently, this can be done in the Advanced tab by loading the Power Management Settings defaults for a Desktop or Mobile processor (depending on the model you have). To automatically use these settings every time you launch RMClock, please check "Remember these settings" option.

    Third, even if your motherboard is properly set up for AMD Cool`n'Quiet(tm) operation, you may experience problems with PST management if you have two or more memory modules installed, even with official AMD processor driver's management. In most cases, it is possible to solve this problem by applying the defaults for Registered DIMMs in the Clock Power/Timing Settings of the Advanced page. Once again, to automatically use these settings whenever you launch RMClock, please enable "Remember these settings" option.

    If none of the above help, try updating your motherboard BIOS to the latest version. If this still doesn't help, we're sorry to inform you that you have a motherboard which is incompatible with AMD Cool`n'Quiet(tm) technology. RMClock does support a greater number of motherboards than the official AMD driver does, but it's not possible to support all of them in software, the compatibility must also exist on a hardware/motherboard design level.

    Q: I have an overclocked system that locks up when I exit the utility (or disable PST management), what to do?

    A: The problem is related to the "Restore CPU Defaults on Exit" setting, which is enabled by default. This setting causes the hard-coded CPU defaults (FID and VID) to be applied when you exit the utility or completely disable PST management. If your FSB clock is too high, the resulting CPU frequency is very likely to go beyond the safety margin. You can either totally disable this feature or alter its functionality so that it applies the FID/VID settings it found at the program startup instead of the CPU defaults (see RMClock_Tweaks.reg file).

    Q: My processor is detected as an "Unknown CPU". What's wrong? Will RMClock work properly with my CPU?

    A: It means that you have a new CPU core/revision, which RMClock isn't yet aware of. The CPU detection is implemented according to the official docs from the vendors, which are not updated as frequently as the new processors get launched. There's nothing to worry about, RMClock will work properly with your processor, provided that it supports the necessary power-saving features (as indicated in the "PM Features" box in the General page).

    Q: The core frequency/throttle of my Athlon 64 CPU reported by RMClock stays the same, despite the FID changes. What's wrong?

    A: This is the OS implementation bug. It is usually observed on a multiprocessor systems (including AMD multi-core processors), when ACPI Multiprocessor PC kernel is used, as well as on a current Windows XP x64 Edition release, regardless of the kernel type. The problem is related to the High-Performance Counter (HPC) featured by the OS. Normally, the ACPI timer is used as a clock source for this counter, when the processor's Time Stamp Counter (TSC) frequency is known to get changed over time (as it does on a Cool`n'Quiet(tm)-enabled system). However, some OS implementations/kernels, like those mentioned above, erroneously choose TSC as a source of HPC clock, thus violating the main requirement for this counter (the frequency of HPC is guaranteed not to change over time). Since HPC frequency is no longer constant and changes in line with TSC frequency, we are getting incorrect TSC/HPC ratio and, therefore, incorrect CPU frequency indication.

    Fortunately, a solution exists for this bug, and it requires editing the boot.ini file found at the root directory of your system disk drive (e.g., C:\boot.ini). To force the OS use the ACPI timer as HPC clock source, you need to add /USEPMTIMER option to your current system settings, e.g.,

    "multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect"

    should become:

    "multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect /usepmtimer"

    Q: I want to see feature "X" in future versions of RMClock. Would you add it for me?

    A: Feature requests are welcome, however, in order for a feature to be possibly incorporated in future versions of RMClock, it must meet the following criteria:

    Revision History

    RMClock Version 2.05

    RMClock Version 2.0

    RMClock Version 1.8

    RMClock Version 1.7

    RMClock Version 1.6

    RMClock Version 1.5

    RMClock Version 1.4

    RMClock Version 1.3

    RMClock Version 1.2

    AMD64CLK Version 1.1

    AMD64CLK Version 1.0


    Please post your comments and questions regarding RightMark CPU Clock Utility that are not already answered in the FAQ section of this manual at the dedicated CPU RightMark forum. In urgent cases, please contact Dmitri Besedin, main program developer.