No, 2133 MHz does not only run at 1333 MHz. The number 2133 MHz refers to the maximum speed at which the memory module can operate, but it can also run at lower speeds if needed. The actual speed at which the memory module operates depends on the system's configuration and settings. **

Yes, DDR3 1600 is compatible with DDR3 1333. When different RAM modules with varying speeds are used together, they will operate at the speed of the slowest module, in this case, DDR3 1333. This means that the DDR3 1600 RAM will downclock to match the speed of the DDR3 1333 RAM for compatibility. **

In DIN 1333, rounding is done by following specific rules. When rounding to a specific number of decimal places, the digit following the last retained digit is examined. If this digit is 5 or greater, the last retained digit is increased by 1. If the digit is less than 5, the last retained digit remains unchanged. Additionally, if the digit following the last retained digit is exactly 5, the last retained digit is rounded up if it is an odd number, and remains unchanged if it is an even number. **

A Latin sentence containing a PFA esse is an Accusative and Infinitive Construction (ACI). In an ACI, the subject of the main clause is in the accusative case, and the infinitive verb is used to express the action of the subject. The PFA (Perfect Passive Participle) esse functions as the infinitive verb in the construction, with the subject of the PFA in the accusative case. **

The 2666 MHz RAM only running at 1333 MHz could be due to several reasons. One possibility is that the motherboard or CPU may not support the full 2666 MHz speed, so it automatically downclocks the RAM to a lower speed that is compatible. Another reason could be that the RAM is not properly configured in the BIOS settings to run at its full speed. It's also possible that there may be a compatibility issue between the RAM and other components in the system, causing it to run at a lower speed for stability reasons. **

The decision to upgrade the RAM to 1067 MHz or 1333 MHz depends on your specific needs and the compatibility of your system. If your system supports both speeds and you require faster performance for tasks like gaming or video editing, then upgrading to 1333 MHz may be beneficial. However, if your system is not compatible with 1333 MHz RAM or if you do not need the extra speed for your regular usage, sticking with 1067 MHz may be more cost-effective. It's important to check your system's specifications and consider your usage requirements before making a decision. **

The parentheses next to your DDR4 RAM (1333 MHz) likely indicate that the RAM is capable of running at a higher speed, but is currently running at 1333 MHz. This could be due to the default settings of your computer's BIOS or the limitations of your motherboard. You may be able to manually adjust the RAM speed in the BIOS settings to take advantage of its full potential. **

The main difference between DDR3 RAM with 1333 MHz and 1600 MHz is the speed at which they operate. The 1600 MHz RAM operates at a higher frequency, allowing for faster data transfer and better overall performance compared to the 1333 MHz RAM. This means that the 1600 MHz RAM can handle more data at a quicker pace, making it more suitable for demanding tasks such as gaming or video editing. However, the difference in performance may not be noticeable for everyday tasks. **