1600 MHz + 1333 MHz = 800 MHz o.O?

Anurag Waugh

Honorable
Jan 20, 2014
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10,530
I recently got myself a new rig. I had bought 2x2gb = 4gb Ddr3 ram @1333 Mhz 3 years back for my brothers PC. He sold his entire PC other than the ram sticks which he gave me. I had newly bought 4 GB 1600 MHz Corsair RAM which I used along with 1333 Mhz (2x2) GB ram thereby getting a tot of 8 GB. Initially I thought that it won't work but it did.

So I have 8 GB ram at 800 MHz but should I not have it at 1333 MHz? D: please help.... And many times my rig crashes without any overheating or anything. And what is dual channel? o_O Thanks in advance
 
Solution
As your RAM is Double Data Rate, the base clock is half the effective clock.
That is to say, your DDR3 1600MHz RAM actually runs at 800MHz, but handles two data transfers/clock cycle; effectively doubling the data rate.

If your RAM is being listed as running at 800MHz (1600MHz effective) now, the existing 2x2GiB sticks are being overclocked.
This could account for your instabilities and would be the first place I would recommend investigating.
In your BIOS, make sure to set your RAM frequency to 667MHz, or 1333MHz depending on how your particular BIOS lists it.
Your Voltage and Timings should probably follow what is listed on the label for your older 1333MHz RAM DIMMs.

Pavan1

Reputable
Jun 18, 2014
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4,710
i advice you not to use two mix 2 different speed of ram that says about your frequent crashing either use 1333 mhz set or other one but dont mix them they may also have different latencies
i would say u r slowly killing ur pc
 
As your RAM is Double Data Rate, the base clock is half the effective clock.
That is to say, your DDR3 1600MHz RAM actually runs at 800MHz, but handles two data transfers/clock cycle; effectively doubling the data rate.

If your RAM is being listed as running at 800MHz (1600MHz effective) now, the existing 2x2GiB sticks are being overclocked.
This could account for your instabilities and would be the first place I would recommend investigating.
In your BIOS, make sure to set your RAM frequency to 667MHz, or 1333MHz depending on how your particular BIOS lists it.
Your Voltage and Timings should probably follow what is listed on the label for your older 1333MHz RAM DIMMs.
 
Solution
Running RAM in Dual Channel means that you are utilizing the both memory controller channels and will have twice the bandwidth available as running in Single Channel mode.
Generally, you will see two different colored sets of RAM slots on your motherboard.
Each colored set correlates to half of your memory channels.
When adding RAM to your system, you should have matching DIMMs in same colored slots on the motherboard for optiomal performance.

To performance differences between 1333MHz and 1600MHz RAM....
There are virtually none at all in the vast majority of consumer workloads.
So long as you are running everything in dual channel mode (matching sticks of RAM in similarly colored RAM slots), I would not hesitate to lower your RAM clocks if it makes your system stable.

-outlw
 
Your first step should defiantly be to stabilize your system.
Assuming your system was stable before adding the new RAM; set in the BIOS the Frequency, Timings and Voltage from the older and slower RAM set.
Hopefully this will stop your crashing.

You can test for stability using Memtest86+ or MemTest.

To running in Single Channel vs Dual Channel.
There is not really much you can do without removing your new 4GiB single stick or adding another into the system.
Personally though, I would not worry too much about it.
While the reduced bandwidth will probably slow you down a little in some workloads, the performance impact should not be major in the majority of your tasks.

-outlw