• About Us
  • Privacy Policy
  • Advertise With Us
  • Contact Us
Real Hardware Reviews
RHR
  • Home
  • Reviews
    • All Reviews
    • Accessories
    • Processors (CPU)
    • GPU
    • Mobile
    • Games & Software
    • Systems
    • Cases
    • Tablet & Laptops
    • Ram
    • Storage
    • Motherboards
  • News
  • Off Topic
    • How To
    • Cryptocurrencies
No Result
View All Result
Real Hardware Reviews
RHR
  • Home
  • Reviews
    • All Reviews
    • Accessories
    • Processors (CPU)
    • GPU
    • Mobile
    • Games & Software
    • Systems
    • Cases
    • Tablet & Laptops
    • Ram
    • Storage
    • Motherboards
  • News
  • Off Topic
    • How To
    • Cryptocurrencies
No Result
View All Result
Real Hardware Reviews
RHR
No Result
View All Result
ADVERTISEMENT
Home Reviews

The Impact of Mixing RAM Speeds

GaK_45 by GaK_45
July 28, 2017
in Reviews, Ram
The Impact of Mixing RAM Speeds
Share on FacebookShare on Twitter
ADVERTISEMENT
Joseph Joseph Nest 9 Nesting Bowls Set with Mixing Bowls Measuring Cups Sieve Colander, 9-Piece,...
Joseph Joseph Nest 9 Nesting Bowls Set with Mixing Bowls Measuring Cups Sieve Colander, 9-Piece, Multicolored
Joseph Joseph Nest 9 Nesting Bowls Set with Mixing Bowls Measuring Cups Sieve Colander, 9-Piece,...
$36.99
$50.00
in stock
14 new from $34.99
as of May 28, 2025 1:02 am
BUY NOW
Amazon.com
QEP 61205 24 in. Professional Chrome-Plated Steel Thinset and Grout Mixing Paddle for Corded Drills
QEP 61205 24 in. Professional Chrome-Plated Steel Thinset and Grout Mixing Paddle for Corded Drills
QEP 61205 24 in. Professional Chrome-Plated Steel Thinset and Grout Mixing Paddle for Corded Drills
$17.87
$21.64
in stock
21 new from $14.14
as of May 28, 2025 1:02 am
BUY NOW
Amazon.com
HERCOO Under Hood Lights Assembly Lamp Kit Compatible with Dodge Ram 1500 2500 3500 Dakota...
HERCOO Under Hood Lights Assembly Lamp Kit Compatible with Dodge Ram 1500 2500 3500 Dakota Charger, Wrangler Grand Cherokee Concorde Dakota , Pack of 1
HERCOO Under Hood Lights Assembly Lamp Kit Compatible with Dodge Ram 1500 2500 3500 Dakota...
$16.99
in stock
as of May 28, 2025 1:02 am
BUY NOW
Amazon.com
Last updated on May 28, 2025 1:02 am
Jump to section

3. New and Old in One

  • 1. Overview
  • 2. The Common Scenarios
  • 3. New and Old in One
  • 4. Testing Methodology
  • 5. Software Benchmarks
  • 6. Gaming Benchmarks
  • 7. WinRAR & x256 HD Benchmarks
  • 8. Performance Summary
  • 9. Closing Statement
The Impact of Mixing RAM Speeds 3

So you have just completed your upgrade to say a shiny new Ryzen 7 system and while you were picking up all the other goodies you saw this great deal on set of 2x8GB DDR4 ram… and just had to have it. You knew that you already had 2x8GB but the idea of having 32GB of RAM was just too much to pass up.

Joy! You just finished building the system… and it worked fine. Party on mate. You got lucky. Most of the time it the opposite happens and it did not want to work with all your RAM installed. You then call us to help find the Gremlin. It is easy to troubleshoot. It’s the new and old RAM are ‘incompatible’ with each other at their stock settings. As in the rig works fine with the old installed, or the new installed but will not even POST with all installed.

ADVERTISEMENT

Why is this? Simple. Your old ram is say DDR4-2133 1.2v with specs of 17-17-17 and your new kit is DD4-3200 1.35v with specs of 15-17-17… and even with all sticks getting 1.35 volts of power that old ram can’t handle the speed nor the timings of the new.

At this point peeps who don’t call us simply stick the new in… and sell the rest. That may indeed work but it doesn’t make for an interesting review. Instead you get ornery and want to make it all work. So how do you do it?

First we tell you to shut the system down and pull all the RAM. Now write down the timings and voltage requirements for both sets.

This is where the three scenarios come into play.

The Impact of Mixing RAM Speeds 4

The timings and maybe even speed are different but the voltages are the same. This one is fairly easy. Simply install only the slowest set of RAM, boot up the system and then enter the BIOS.

The Impact of Mixing RAM Speeds 5

When there you tell the BIOS you want to overclock the RAM manually. This includes turning off XMP and the like, and then turning on ‘RAM overclocking’ options – the specific name will vary from manufacture to manufacture and even series to series. When this is done you will have full access to not only the RAM timings but also the voltage requirements.

Since both the old and new RAM are the same voltage simply manually hard setting the RAM timings to what ever is the slowest. When we say hard setting the timings, this includes the speed at which the RAM is operating and not just the latency. For example DDR4-2133 at 17-17-17 is an entirely different beast from DDR4-3200 at 17-17-17!

The Impact of Mixing RAM Speeds 6

While typical motherboards don’t allow for individual memory channel speeds, the timings of each channel can sometimes we tweaked – so make sure that both A and B channel are the same. With this done save the BIOS to one of the BIOS save points and then save and exit the BIOS. Now if you want you can let the system reboot and power up… but we recommend as soon as the system starts to POST doing a hard shutdown.

The Impact of Mixing RAM Speeds 7

Then move one of the old memory from channel B #1 slot one to channel A slot #2. Now install the new into both slots of channel B. At this point the rig will power up and usually play nice as the new faster RAM is simply being underclocked with looser timings. Enter the BIOS and check to make sure that both channel A and B settings are still the same. At this point you should be good to go.

If you so choose you can start playing around to see how far the old RAM will go speed wise but this is entirely up to you and will consist entirely of trial error. Maybe you have to push the voltage on both the new and the old to get it to work at some point between the new and old RAM speed. For example the old RAM is DDR4-2400 and the new is DDR4-2800… but the system will actually POST and work with DDR4-2666 speeds. It really will be a throw of the dice and will be all up to the old RAM’s ability to be overclocked as the newer RAM will be ‘underclocked’.

The Impact of Mixing RAM Speeds 8

Usually people who buy and inadvertently mix and match RAM do not get so lucky on their impulse buy of RAM… and the new kit is 1.35v RAM that simply is not stable at 1.2v at the old RAM speed. This actually is because the old is using 1.2v and that is what the computer is reading as the ‘proper’ voltage setting. In this case when you do the ‘best case’ scenario steps the system does not POST as it is not the old but the new that is causing the problem.

So what do you do? You did all the best case steps and the system wont POST… so you pull the new sticks, and reinstall the old so they populate both memory channels and reboot the rig… and enter the BIOS. This is where things can go one of two ways. If you are lucky your motherboard allows channel A and channel B to not only having different timings but also different voltages. Simply set the Channel B voltage to 1.35v, save to the BIOS and then power down the rig. Redo the RAM swap you did before and power the rig up again. This usually is all that is needed as the 1.2v RAM is being a fed a healthy diet of 1.2 while the new is being fed 1.35.

The Impact of Mixing RAM Speeds 9

Unfortunately, not that many motherboards outside of the rare ‘overclocking’ motherboards allow you to set the voltage individually. It really will come down to how advanced your motherboard is. So if it’s a cheap board you may not be able to get by with this middle of the road solutions as the system will still not POST.

At this point you have three options. Option A is to give up, sell the old RAM and buy another kit of the new. Option B is to lower the ram speed to DDR4-2133. We have yet to find a set of DDR4, even high-performance kits, that won’t work at DDR4-2133 at 1.2v-1.3v. Try it, test it… and then push up a level at a time until you find how fast is too fast.

Option C is to feed the old RAM more voltage than it is rated for. If you are in a hurry you can simply set it to 1.35v and be done with it. The old RAM may not live as long as it rated for… but much like overclocking a CPU a little bit of extra voltage will not reduce the lifespan enough to matter.

The more optimal solution is try 1.30v and see if all the RAM is stable via stress testing. If it passes a 24hr burn in… lower the voltage. You will end up with a compromise that both sets of RAM can work at in regards to both speed and voltage.

Jump to section

3. New and Old in One

  • 1. Overview
  • 2. The Common Scenarios
  • 3. New and Old in One
  • 4. Testing Methodology
  • 5. Software Benchmarks
  • 6. Gaming Benchmarks
  • 7. WinRAR & x256 HD Benchmarks
  • 8. Performance Summary
  • 9. Closing Statement
Page 3 of 9
Previous 123456789 Next
ADVERTISEMENT
GaK_45

GaK_45

"Knowledgeable, opinionated and not afraid to ask the questions you can’t or won’t." GaK_45's combination of multiple industry certifications(MCSE, CCNA, various CompTIA, etc), and over twenty years' experience in the computer industry allows him to provide detailed analysis that is as trustworthy as it is practical.

Next Post
Galaxy A5 the best mid-range phone

Galaxy A5 the best mid-range phone

Leave Comment

Recommended.

ASUS Launches Zenbook 14 OLED with Intel Core Ultra

ASUS Launches Zenbook 14 OLED with Intel Core Ultra

December 14, 2023
MSI 970A SLI KRAIT Review

MSI 970A SLI KRAIT Review

August 4, 2015
ADVERTISEMENT

Trending.

Crucial Pro DDR5-5600 128GB Review

Crucial Pro DDR5-5600 128GB Review

Seagate Exos X18 Review

Seagate Exos X18 Review

MSI BE6500 WiFi 7 USB Review

MSI BE6500 WiFi 7 USB Review

Seagate Exos X24 Review

Seagate Exos X24 Review

Seagate IronWolf Pro 24TB Review

Seagate IronWolf Pro 24TB Review

Real Hardware Reviews

© 2013 - 2024 | Powered by Real Hardware Reviews

Navigate Site

  • Home
  • About Us
  • Contact Us
  • Privacy Policy
  • Terms and Conditions
  • Editorial & Disclosure Policy

Follow Us

No Result
View All Result
  • Home
  • Reviews
    • All Reviews
    • Accessories
    • Processors (CPU)
    • GPU
    • Mobile
    • Games & Software
    • Systems
    • Cases
    • Tablet & Laptops
    • Ram
    • Storage
    • Motherboards
  • News
  • Off Topic
    • How To
    • Cryptocurrencies

© 2013 - 2024 | Powered by Real Hardware Reviews

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.