NVSU is a collection tools, starting with “Overclocking Basic”. This lets you set FSB, AGP, Memory speeds on the fly. It also lets you change memory timings or voltages of CPU, AGP and others on the fly. With this tool you also have the ability to change fan speeds on the fly.
The second tool within NVSU is the “Overclocking Advance” tool”. This is a windows based BIOS interface. As the name suggest, you can configure slightly more advanced settings here. *This page is not accessible if your BIOS doesn't support it.
The third tool is an “Information” tool which serves the same purpose such as WCPUID or CPU-Z only slightly more advanced.
Last is a graphical monitoring tool, somewhat similar to that available in Motherboard monitor or CPUCool.
When you start NVSU (after agreeing to the license agreement that says NVIDIA is not responsible if you fry your hardware when you first start it) you will be greeted with the screenshot given below. This is the “Overclocking – Basic Tool”
Overclocking – Basic Section
NVSU – Overclocking - Basic Page
This is “Overclocking – Basic” page as you can see from the title of the window. You can see from the screen capture (taken from the user guide), this page is divided into 4 panels. On the top left on the page is the “Bus speeds” panel. On the top-right is the “Memory controller timing” panel. On the bottom left, you have the “Voltages” panel and on the bottom right, the “Fan Speeds” panel. This is the screen you will get of your BIOS supports all functionality of the NVSU. If not, you will get one like below, which is of NVSU on an ABIT NF7-S Version 2.0 motherboard. Notice the, “Voltages” and “Fan Speed” panels are missing.
NVSU Overclocking Basic Panel with an ABIT NF7-S v2.0
NVSU - Bus Speeds Panel
Here in this panel, NVSU lets you change the CPU FSB, memory and AGP bus speeds. To do so, all you have to do is adjust the sliders right to increase the clock or adjust the sliders to the left to decrease the clocks, easy as that! This doesn’t require support to be enabled through BIOS by OEMs.
FSB/Memory Bus Speeds
NVSU – FSB/Memory Adjustable Slider
For nForce2 motherboards, the FSB and Memory adjustable area is displayed top of AGP adjustable area, and speeds are reported in DDR format. (NVSU will also report FSB and memory speeds in MHz only). You can set the FSB upto 25% higher from the reference FSB when overclocking and set the FSB 50% lower than reference when underclocking. This is great but the astute among you might have noticed that there is only one slider that encompasses the FSB and memory tweak area. Therefore, you cannot adjust the clock speed of the CPU FSB or memory separately. This is “due to a limitation in the chipset”. In another words memory dividers cannot be manipulated through this utility which is a shame but, nothing can be done because it is a hardware limitation. This may seriously detract the hardcore of overclockers, or overclockers who do not have expensive memory rated something silly like DDR500. But, where there is will, there is definitely a way.
What this obviously means is that when you overclock the FSB, the memory bus clock also increases or decreases correspondingly depending on what you do with the CPU FSB clock. After you have adjusted the slider to the required the value, you can then press the “OK” or “Apply” button to get NVSU to commit the new settings. The only difference being that if you press the “OK” button, NVSU will close itself after applying the new settings whereas, clicking the “Apply” button won’t and NVSU will remain open. Also as all of you know, increasing the FSB may also cause the CPU to heat up more. Be sure to invest in a decent HSF or you may end up shortening it’s lifetime to completely frying your CPU.
NVSU supports adjusting the FSB/Memory speed in synchronous or asynchronous mode but, just be aware that, if you increase the FSB speed, the memory speed also increase in direct proportion.
All of this also applies to nForce3 motherboards too, only instead of CPU FSB, the Hypertransport bus is reported. It is displayed as DDR format as well but with the LDT multiplier factored in with the actual bus speed. In which case, the LDI multiplier is 3, and so the Hypertransport will be displayed as (400MHz bus multiplied by 3 which is) 1200MHz. So adjust the slider as you wish and click either the “Apply” or “OK” button to set the new bus clock.
AGP Bus Speeds
NVSU – AGP Speed Adjustable Slider
The AGP adjustable slider is located below the CPU FSB/Hypertransport and memory slider. Here, users can adjust the AGP via the slider to what they prefer. This feature is only meant for external AGP devices and hence, users with integrated graphics cannot use the NVSU to change their AGP bus speeds. This applies to nForce3 motherboards as well.
NVSU – Voltages Group Panel
In this panel, NVSU allows you to tweak voltages of the CPU, memory, AGP and auxillary. This panel is only available if your BIOS has support enabled for this function of the NVSU. The panel is easy to figure out, for users who want to overclock their CPU to the extreme; a little tweakage in the form of a CPU voltage boost might result in getting the desired effect, stability at higher clock speeds. The CPU voltage is increased or decreased by adjusting the slider and then pressing the “OK or “Apply” button. Increasing the CPU voltage will also cause the CPU to even heat up more, so please do be careful.
Memory voltages can also be changed through the “Voltage” panel. All you have to do is select the new value from a drop down box. Tweaking the voltage for memory maybe required because the FSB and memory bus speeds increases with the same increment as they are tied together. Tweaking the memory voltage may allow your memory to run at higher clock speeds.
You can also tweak the AGP voltage here by selecting the desired voltage through a drop down menu. Doing so might boost your efforts to overclock you video card. Its as always not totally guaranteed, that it will. You can also tweak other voltage settings here such, as Auxiliary and nForce voltages through a drop down menu as well. nForce voltage settings refers to the nForce SPP chip voltage itself. Increasing the voltage on this setting may help you reach higher CPU FSBs. The auxiliary voltage is used to adjust the setting for the voltage “available to the system while in a power saving mode like suspend”.
If your motherboards BIOS supports it you can get a graph representation of temperature, speeds and voltages as shown below by clicking the “Toggle Graph View Button” button. This screen capture was with NVSU and my ABIT NF7-S v2.0 motherboard.
NVSU with Graph Display
The temperature graph shows you temperatures as reported by the BIOS. On the screenshot above, NVSU displays my die temperature as reported by my BIOS. The other temperature displayed is my system temperature. Interesting to note that, the temperature reported were way higher than what was reported with other temperature monitoring utilities such as ABIT’s Hardware Doctor or Motherboard Monitor. NVSU also takes into account “CPU Overtemp” level which is shown as a red line on the CPU temperature graph. If the temperature jumps over the “CPU Overtemp” line, the bar graph will turn red. The polling interval can also be configured through a drop down menu.
Voltages are also shown in the form of graphs with numerical values on top. These are as reported by the BIOS. The red line on top are the maximum value you are allowed to tinker with the yellow line being the default value. NVSU has been hard coded to show green graphs for safe levels, yellow graphs to show a warning, that at that reported voltage, it is running out of recommended settings. Red graph means that you are way beyond safety limits. To get these graphs, you BIOS must support this feature.
Speed graphs are shown without the support from BIOS. There is also a numerical value as reported by the BIOS of the various bus speeds. The yellow line going across meaning it’s at default whilst the red line suggests that that is the maximum value allowed.
Memory Controller Timing
NVSU – Memory Control Timing Panel
This panel is supported by all nForce3 and nForce2 motherboards and shouldn’t require support through BIOS according to NVIDIA. On this panel, you can change 3 memory controller related settings, the tRAS (Row Address Strobe), tRCD (RAS to CAS access), and tRP (Memory Bank Switch). You can set tRAS values from 1 to 15 with 1 being the most aggressive timing and 15 being the least. tRCD and tRP values can be set through 1 to 7, the higher the value the more relaxed timing. These settings are adjustable via drop down menu. You simply select the desired value and click “Ok” or “Apply” button. These settings are also important in achieving a stable system when overclocking because the CPU FSB and memory are increased by the same increment you choose in the “Bus Speed” panel. Setting higher values for these three settings (and CAS latency) may make your memory and hence your system, more stable. (You may also notice that CAS latency setting is missing but, fear not, it is available but in the “Overclocking _ Advanced Section”).
NVSU – Fan Speeds Panel
BIOS support is also needed for this panel or it will not be accessible through the NVSU. As you can guess you can change the speed by adjusting the sliders. This will either decrease or increase the rpm’s for the fans for the CPU’s heat sink fan or auxiliary fan (which I am guessing this is in reference to the chassis fan). This is boon for users who like to keep the decibel levels low from high rpm fans for heat sinks (such as deltas fans) when you do not need to cool your CPU (i.e. when idle, browsing the internet or listening to mp3s) as intensively as you do when gaming.