XMP with Corsair Vengeance LED 32GB + Gigabyte GA-X99-UD4

[socialwaif]

I was looking to make use of the XMP profile setting on my Corsair Vengeance LED RAM. It is model number CMU32GX4M4C3000C15B. Listed as DDR4 3000. It is currently running at a lower, default speed. Around 2132 (1066 MHz) according to CPUID.

 

I am new to this. What all do I have to do to make use of the higher speeds through XMP? I could use some help or a simple "How-To" style Walkthrough as to what to expect. Do I just turn on or enable the XMP profile? Or are there other settings, like voltages, that need to be changed as well?

 

My CPU is a Haswell-E, Intel® Core i7-5820K CPU @ 3.30GHz. My motherboard is a Gigabyte GA-X99-UD4.

[c-attack]

Yes, you just "turn on" the XMP setting in your BIOS. What this looks like is different for each manufacturer. When you do that, the BIOS will change some settings automatically in accordance with the information on the module (timings, DRAM voltage). Other settings will be changed automatically in accordance with your BIOS programming. Some of these might include System Agent voltage (SA or VCCSA) and the strap or Base Clock (BCLK).

 

The system should boot on its own with these settings, but like most one-click overclocks, it usually possible to refine the settings to more desirable levels. System agent voltage is often over-boosted, however the one of the most immediate interest may be your base clock or strap. 125 is the natural multiplier for 3000 MHz memory frequency. When you at that setting, you will loose your adaptive voltage and it will run at a fixed level. Some BIOS systems allow you manually set it back to 100, while retaining the 3000 DRAM frequency. Others will not and XMP locks most other settings. I would need your exact board to know, but someone else may have it. For now, you can enable XMP, boot, and observe.

[socialwaif]

Yes, you just "turn on" the XMP setting in your BIOS. What this looks like is different for each manufacturer. When you do that, the BIOS will change some settings automatically in accordance with the information on the module (timings, DRAM voltage). Other settings will be changed automatically in accordance with your BIOS programming. Some of these might include System Agent voltage (SA or VCCSA) and the strap or Base Clock (BCLK).

 

The system should boot on its own with these settings, but like most one-click overclocks, it usually possible to refine the settings to more desirable levels. System agent voltage is often over-boosted, however the one of the most immediate interest may be your base clock or strap. 125 is the natural multiplier for 3000 MHz memory frequency. When you at that setting, you will loose your adaptive voltage and it will run at a fixed level. Some BIOS systems allow you manually set it back to 100, while retaining the 3000 DRAM frequency. Others will not and XMP locks most other settings. I would need your exact board to know, but someone else may have it. For now, you can enable XMP, boot, and observe.

 

Thanks for the information. It gives me a good idea of what to expect.

[socialwaif]

I went into my BIOS or EUFI today to poke around. Looking for what settings were there and what the various options were. Howeverr, I did not see anything obvious by the name of SA or VCCSA, more a mention of a strap. There was a setting for the Multiplier though.

 

I took a few screenshots to show what was in there, which I added as attachments.

[c-attack]

My guess is those two items will be in the Frequency and Voltage tabs. However, I have never owner a Gigabyte board, so that is nothing more than an educated guess. These things are not always logical. Strap is an Asus term. I don't know what Gigabyte calls it, but you will notice if it changes. Instead of everything being multiplied by 100, it will change to a 125 MHz multiplier. The BIOS will adjust everything automatically to compensate, but the real casualty is the loss of adaptive voltage.

 

In both shots, you have XMP disabled so I can't see anything of relevance. Go ahead and enable and boot up. There should not be any short term repercussions, but over the long term you would like it be efficient.

 

*Also - It looks like that is a fairly old BIOS. You may want to look for a recent version. Huge gains in DDR4 stability from the early days of the X99 platform.

[socialwaif]

My guess is those two items will be in the Frequency and Voltage tabs. However, I have never owner a Gigabyte board, so that is nothing more than an educated guess. These things are not always logical. Strap is an Asus term. I don't know what Gigabyte calls it, but you will notice if it changes. Instead of everything being multiplied by 100, it will change to a 125 MHz multiplier. The BIOS will adjust everything automatically to compensate, but the real casualty is the loss of adaptive voltage.

 

Thanks, I will recheck those two areas. Also looking up for the term that Gigabyte might be using instead of strap. One thing I saw online that discussed it refered to it as the "Processor Base Clock (Gear Ratio)" at https://forums.anandtech.com/threads/haswell-bclk-strap-overclocking-anybody-have-luck.2324065/

 

 

*Also - It looks like that is a fairly old BIOS. You may want to look for a recent version. Huge gains in DDR4 stability from the early days of the X99 platform.

 

Oh, yeah, the last time I updated my BIOS was a good while back. Around when the first NVMe SSDs were coming out. Something else for me to look into. Thanks.

[socialwaif]

Hey, thanks for the suggestion about updating my BIOS. The UEFI interface is much improved. I am still getting used to the new version. It is quite different. Loving it so far.

 

My boot drive is an NVMe M.2 SSD. The old UEFI did not properly identify it. The previous BIOS update I did was to enable support for NVMe drives.

 

I am looking to do the tweaks to use XMP around the 13th of this month. End of the semester and work.

 

I had a question though. If I tweak the frequency of the RAM (via XMP) will that also affect the settings for my CPU? Some of the stuff I have looked at online about overclocking covered both areas. I was not certain if they could be adjusted independently or not.

[c-attack]

It does not necessarily change your CPU frequency and multiplier. The "strap" or "gear ratio" is a multiplier applied to both DRAM and CPU clocks. Some memory frequencies work better with a specific gear. The normal ratio is "100" which is what most people are used to. Set the CPU multiplier to 40 and you get 4000 MHz or 4.0 GHz clock speed (40x100). However, the 2800 and 3000 memory speeds are often paired with the 125 "gear" and that is applied to memory and CPU overclocking. The memory you don't need to worry about as the XMP preset and BIOS will be set automatically change the multiplier to match. However, the most common thing to happen on the CPU side is for it to reset to the factory frequency, using the 125 x 27 = 3.375 GHz. You probably have to reset the multiplier to reach your desired CPU frequency, if you were overclocking. So 125 x 32 = 4.0 GHz, 125 x 36 = 4.5 Ghz, etc. That only takes a moment, but can be confusing if you were not expecting it.

 

I do not know if Gigabyte will let you change the gear back to 100 or if it even changes it to 125. This is BIOS version specific. Early versions mandated the 125 gear for everyone . That was relaxed later in the product cycle on some BIOS versions. This really would not matter at all, except you cannot use adaptive voltage while on the 125 gear. If that is important to you, it may be possible to either force the gear back to 100 or try to extend the overclock to 3200 on the memory by manual means. The 3200 frequency will allow the 100 gear as the natural ratio.

[socialwaif]

Thanks for the reply. Good to know. I am still learning this stuff. The information about the "gear" may need to be taken up with Gigabyte themselves or on their own user forums.

[c-attack]

You can ask them, although it will become pretty clear is this happens right after enabling the XMP switch. Whether or not you are physically able to change it to 100 can be learned in a moment. Whether or not it would be stable at 100, will take a lot more moments. Again, this only really matters for most people if they want to run adaptive voltage and there are other options.