Determine maximum RAM speed

Question

I want to buy new RAM for my laptop and wondering if my motherboard supports DDR3-1600. This is the output of dmidecode -t 17:

# dmidecode 2.11
SMBIOS 2.6 present.

Handle 0x002D, DMI type 17, 28 bytes
Memory Device
    Array Handle: 0x002C
    Error Information Handle: No Error
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 2048 MB
    Form Factor: SODIMM
    Set: None
    Locator: DIMM 1
    Bank Locator: Bank 0/1
    Type: DDR3
    Type Detail: Synchronous
    Speed: 1334 MHz
    Manufacturer: 80CE            
    Serial Number: 67089954        
    Asset Tag: 1051
    Part Number: M471B5773CHS-CH9  
    Rank: Unknown

Handle 0x002E, DMI type 17, 28 bytes
Memory Device
    Array Handle: 0x002C
    Error Information Handle: No Error
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 2048 MB
    Form Factor: SODIMM
    Set: None
    Locator: DIMM 2
    Bank Locator: Bank 2/3
    Type: DDR3
    Type Detail: Synchronous
    Speed: 1334 MHz
    Manufacturer: 80CE            
    Serial Number: 6708993D        
    Asset Tag: 1051
    Part Number: M471B5773CHS-CH9  
    Rank: Unknown

Handle 0x002F, DMI type 17, 28 bytes
Memory Device
    Array Handle: 0x002C
    Error Information Handle: No Error
    Total Width: Unknown
    Data Width: Unknown
    Size: No Module Installed
    Form Factor: SODIMM
    Set: None
    Locator: DIMM 3
    Bank Locator: Bank 4/5
    Type: Unknown
    Type Detail: Synchronous
    Speed: Unknown
    Manufacturer:                 
    Serial Number:                 
    Asset Tag:     
    Part Number:                   
    Rank: Unknown

Handle 0x0030, DMI type 17, 28 bytes
Memory Device
    Array Handle: 0x002C
    Error Information Handle: No Error
    Total Width: Unknown
    Data Width: Unknown
    Size: No Module Installed
    Form Factor: SODIMM
    Set: None
    Locator: DIMM 4
    Bank Locator: Bank 6/7
    Type: Unknown
    Type Detail: Synchronous
    Speed: Unknown
    Manufacturer:                 
    Serial Number:                 
    Asset Tag:     
    Part Number:                   
    Rank: Unknown

So currently i have not installed DDR3-1600.

How can I determine if DDR3-1600 is supported?

EDIT: my CPU is Intel(R) Core(TM) i7 CPU Q 720 @ 1.60GHz if that's important.

kind regards

Solution 1

As pointed out in the comments of your question, your CPU does not support a RAM frequency of 1600MHz. Not to worry as there is virtually no performance difference between 1333MHz and 1600MHz when it comes to real life usage. It's only when you're bench-marking that you'll see a difference.

I'm assuming you want the upgrade for gaming purposes. In that case it is very likely you will not see any significant gain. If you search the term 1600MHz vs 1333MHz, you'll find many sources quoting that the difference is not at all noticeable.

You could always go into your BIOS and see if you can change some settings to try and improve performance. Obviously you'll have to be very careful as you could potentially render your system unusable. If you've never overclocked before in any capacity, I would suggest reading up on it before changing anything. If you still feel uncomfortable making changes in the BIOS, it is better just to leave it alone.

As for the higher frequency RAM, you can certainly use it, but it will default to 1333MHz as that's the highest supported frequency. If the RAM timings for the 1600MHz RAM are tighter, you could potentially see some performance gains.

Some information about RAM timings from Hardware Secrets

Timings measure the time the memory chip delays doing something internally. Here is an example. Consider the most famous parameter, which is called CAS Latency (or CL or “access time”) that tells us how many clock cycles the memory module will delay in returning data requested by the CPU. A memory module with a CL 9 will delay nine clock cycles to deliver a requested data, whereas a memory module with a CL 7 will delay seven clock cycles to deliver it. While both modules may run at the same clock rate, the second one will be faster, as it will deliver data sooner than the first one. This issue is known as “latency.” As you can see in Figure 1, the module portrayed there has a CL of 7.

As another example if the timings of your current RAM are 9-9-9-24-1T and the timings of the 1600MHz are 7-7-7-21-1T, the 1600MHz RAM will have a shorter delay when data is requested. If the price of the RAM is similar and the timings are better, you can by all means use the 1600MHz RAM, but you won't be able to make use of the maximum available performance.

Solution 2

Your motherboard supports DDR3-1600 RAM but will only run it at DDR3-1333 speeds. You will, however, usually get lower latency if you use faster RAM.

Comments

[Admin]

That output specifies the current speed of the ram installed, not the supported speed of the chipset/cpu. Post the specific CPU product code and that will allow someone to determine its supported memory speed

[Admin]

per ark, your CPU will not support DDR3-1600. ark.intel.com/products/43122/…

[Admin]

The motherboard has to support it and the CPU has to support it - both usually mention max RAM size in their specifications. If you manage to get higher frequency RAM working, it will probably be clockeddown to max. supported. Also it usually gets clockeddown to the lowest frequency among other RAMs. (If you have 667Mhz and 1600Mhz, the 1600Mhz will get clocked down to 667Mhz) To find MB model - askubuntu.com/questions/179958/… , to find cpu model use command lscpu or system information GUI.

[user1291235]

I am upgrading primary because i need more RAM for Virtualization. However, excellent answer. Thank you!

[Yass]

You're welcome. More RAM will definitely help for Virtualization. You don't really need to worry about speed all that much.