Desperately needs help finding the right Corsair V LPX RAM for my DAW PC..

Hi there!

I'm a newcomer to this forum and I've spent the last few days trying to find some Corsair Vengeance LPX RAM for my new DAW PC. I've used Corsair RAM before so I'd like to go the same route again. However, finding the right RAM would prove more difficult than I remember it to be. Well It’s been a few years since I put together a PC.. :o: After checking out the QVL list and becoming no wiser I thought I'd ask here, hoping for some guidance through this jungle of RAM speeds/sizes/CAS latency values and what have you.

Btw, I intend to run the CPU and RAM at the "default factory speeds", so no overclocking. I bought the unlocked version of the CPU because of the slightly higher base speed. The computer will be used for music composition and audio recording/editing. No resource-hungry graphics like gaming and video editing. But sample libraries often demands a lot of RAM and fast streaming of samples from HDD/SSD. VST instruments and other plugins can also be very demanding of the CPU, so I though I'd put together a reasonably fast DAW PC for those tasks - without going into overclocking territory, of which I know nothing about.

I would like to get the fastest RAM speed officially supported for my motherboard and CPU (ASUS Prime Z-270-A and Intel Core i7-7700K). Would that be 2133 MHz or 2400 MHz? Looking at the documentation for the processor it says "DDR4-2133/2400", but the documentation for my motherboard says 2133MHz and "2400 (O.C)", which I suppose means overclocked? I'm confused.. :confused:

I'd like to install 32GB RAM to begin with, having the option to max out at 64GB if there would be a need for that. So I guess I'm looking at a set of two 16GB sticks, with the possibility of buying the exact same set of 2 x 16GB sticks later on.

However, what confused me when looking at the Qualified Vendors List for my motherboard is this column saying "DIMM socket support (Optional)". Would I be looking for a set of Corsair RAM (2 x 16GB) that has a dot in the "4 DIMM" column, since I would eventually like to be able to put in a total of four 16GB sticks? If that's the case I can't seem to find that listed under 2133MHz, and there doesn't seem to by any 2 x 16GB sets listed at all in the 2400MHz section.

And then there seems to be several versions sharing the same RAM speed but with different CAS latency timings. I suppose I should choose the sets with the lowest numbers?

I’m also curious if would be able to get lower CAS latency timings if I bought a Vengeance LPX RAM set with a higher clock speed (for example 3000MHz or 3200MHz) and then “downclocked” the speed to the officially supported 2133MHz or 2400MHz. Or would that make the RAM unstable somehow? If it’s even possible that is.. I seem to remember reading about that somewhere.

So – a set of two good quality 16GB RAM sticks, Corsair Vengeance LPX (Black). Compatible with my motherboard and processor. I tried hard for days, but now I ask ever so kindly for your help. This was perhaps a long post, but I’d really appreciate if someone could help me get some clarification to the questions above. Thank you!

Motherboard makers tend to put some slightly misleading information on their product pages. Graphics showing what happens when you run 1.80 Vcore or benchmarks at an unattainable 5.2GHz don't really help. As for memory frequency, 2133 is JEDEC standard and when push comes to shove, that is the "default" speed. All DDR4 memory kits must be able to run 2133 MHz with an exact of set of timings. Any kit you buy will be capable of running 2133. What you see on the product page are the "XMP" available speeds. The XMP is a 'one touch overclocking system' for memory. Enter your BIOS, check XMP box, memory settings for a higher frequency are applied. Some memory can run just slightly faster or with slightly tighter timings than the XMP speeds, but this is not guaranteed and must be done manually. Every single kit, from every manufacturer, will use the exact same 2133 (15-15-15-36) timings when you plug them into the board.

If you want to use better timings for theoretically less latency, you must manually enter them in the BIOS. It is not as daunting as it sounds, but anything other than 2133 (15-15-15-36) is technically overclocking. That should not matter. Every single Kaby Lake CPU and Z170 board should be able to run to 2666 without issue. I am assuming for your DAW purposes, you are looking for the lowest latency possible. However, you should know that CAS latency (the first number on the memory timings) does not directly mean the memory operation as a whole has less latency. The operation latency is sum of several actions, of which frequency plays a part. On DDR4, you generally will see better operational latency as you get to higher frequencies. My 3200 MHz will have lower latency than 2133, no matter how much I tighten my timings at the lower speed. This actual values are very CPU/motherboard/memory specific. However, if you note the pricing on the 2x16 kits, there isn't much difference between a 2400 kit and a 3000 kit.

My recommendation is to spend the $10 more and get the highest frequency kit, with the lowest CAS latency (C14, C15, etc). Most memory kits will be able to drop a C-rung for each standard step down in frequency. So, a C15 3000 kit can likely run C14-2800, C13-2666, C12-2400, C-11 2133. This is a general rule and each batch has its own properties. Things are not always so linear.

I don't use your DAW applications and I don't have an answer whether you will get better results at JEDEC 2133, 2133 C11, or 3000 C15. However, you don't have to choose now if you go with a higher kit. I don't know where you are and prices vary from region to region. Using the prices from the Corsair page, the 3000C15 kit seems like the one to choose. When you first get it, plug them in and your done. Do your work, take observations. Then you can decide if you would like to try tighter timings at 2133, the higher end of the frequency at 3000/3200, or an easy middle ground at 2666. That is doesn't require too much tinkering, but memory overclocking is more difficult than CPU overclocking.

Vengeance LPX Black 2x16 kits

Thanks for your help, c-attack! Now I understand a bit more about this!

So your're saying I would get tighter timings with for example a 3000 MHz kit downclocked to say, 2666 MHz than I would with the standard 2133 MHz?

Also, how is the warranty on those Corsair RAM sticks? If they are tested for a specific speed and I never go above that speed in XMP - but things still go pearshaped, would the RAM be covered by a warranty?

Is 15-15-15-36 the absolute standard timing for 2122 MHz RAM? I've seen many different latency timings claimed on 2133 MHz ram sticks. Does the latency timings stated in the product specifications guarantee that they can be run at those latency timings?

Thanks again! Much appreciated! :-)

2133 (15-15-15-36) are base requirements for all DDR4 modules, whether they are $200 high performance or the cheapest modules made. They all have to run this. As a result, many better memory makers also have a 2133 speed with better timings than C15, but this is an XMP preset and not the default speed. A 2133 C13 kit will only run that speed if you manually set it or enable the XMP preset. However, if is a relatively safe assumption a kit with an 2133 C13 overclock will not run much better, or the manufacturer would advertise it with those speeds.

Don't confuse "tightest timings" (meaning lowest number) with lowest operational latency. The higher speeds will still have better operational latency than the lower one. Whether this matters for your DAW work is a question I cannot answer, but the memory that runs the higher speeds with the lowest CAS latency will also likely run the lower speeds with the lowest CAS latency. Occasionally you will see a kit really tightened down, like a 2400C10 kit, but there is not one available in the product and configuration you requested. I don't know if that has value for you anyway.

I can't really say much about the warranty. It varies from country to country and those law are applicable. I think what you really want to know is if you can return the product if it does not work and that is governed by the vendor's return policy and not the warranty. Corsair generally offers a lifetime warranty for most of their memory products. That should give you a rough estimation of the failure rate -- very low. RAM does not blow up or short out when the speed is too high. The PC will crash or refuse to boot at that speed. We know you don't really want to run upper limit memory frequencies for DAW applications, but the kits at the higher end are also likely to better at the lower end where you are going to run.

2133 (15-15-15-36) are base requirements for all DDR4 modules, whether they are $200 high performance or the cheapest modules made. They all have to run this. As a result, many better memory makers also have a 2133 speed with better timings than C15, but this is an XMP preset and not the default speed. A 2133 C13 kit will only run that speed if you manually set it or enable the XMP preset. However, if is a relatively safe assumption a kit with an 2133 C13 overclock will not run much better, or the manufacturer would advertise it with those speeds.

 

Don't confuse "tightest timings" (meaning lowest number) with lowest operational latency. The higher speeds will still have better operational latency than the lower one. Whether this matters for your DAW work is a question I cannot answer, but the memory that runs the higher speeds with the lowest CAS latency will also likely run the lower speeds with the lowest CAS latency. Occasionally you will see a kit really tightened down, like a 2400C10 kit, but there is not one available in the product and configuration you requested. I don't know if that has value for you anyway.

 

I can't really say much about the warranty. It varies from country to country and those law are applicable. I think what you really want to know is if you can return the product if it does not work and that is governed by the vendor's return policy and not the warranty. Corsair generally offers a lifetime warranty for most of their memory products. That should give you a rough estimation of the failure rate -- very low. RAM does not blow up or short out when the speed is too high. The PC will crash or refuse to boot at that speed. We know you don't really want to run upper limit memory frequencies for DAW applications, but the kits at the higher end are also likely to better at the lower end where you are going to run.

Hey I have these : http://www.corsair.com/en-gb/vengeance-lpx-16gb-2x8gb-ddr4-dram-2666mhz-c16-memory-kit-black-cmk16gx4m2a2666c16

Whats the lowest latency you think these can run at?

I do audio music production and from my experience all the high speed XMP DDR4 RAMs make all audio applications seem to sound a bit drifty and not tight sounding when it comes to playback.

Turning XMP off seems to work better for me, I don't know if it's due to the high freq RAM speeds or the CAS latency.

CAS latency? Starting with listed 2666C16@1.20v, it surely would step down normally to 2400C15 and 2133C14. That is conservative to be sure, but then you don't really want to be testing your memory stability for DAW work. By raising the voltage to 1.35v, you could do better still. I would think 2133C12 would be easy and the cost of increased voltage is DRAM temperature, not latency. You can run 1.35v all day and night and never give it a second thought. Now, whether there is any utility in running 2133C12 vs 2133C14 for your work is another matter and one I can't answer.

Is this for a Z170 Skylake set-up? If not, there might be newer alternatives is the same general category with more upside.