|
Page 3 of 6
Specifications:
The default speed on
this memory is 1066MHz DDR2 or PC2-8500 and the EPP memory
timing is 5-5-5-15 1T (CAS-TRCD-TRP-TRAS).
Now what does DDR, CAS,
tRCD, tRP, tRAS, tCLK, and EPP mean?
DDR:
This
stands for Double Date Rate and that means it doubles the
bandwidth of the memory by transferring data twice as fast
on both the rising and falling of the clock cycle.
CAS (tCL):
This
stands for Column Address Strobe or Column Address Select and
that essentially means the number of cycles for the memory
to get information and then process that information. Also
keep in mind that a lower CAS is much better than a higher CAS,
so try and keep CAS as low as possible when overclocking.
tRCD:
This is the delay from the time a row is activated to when the cell (or column)
is activated via the CAS signal and data can be written to or read from a memory
cell. When memory is accessed sequentially, the row is already active and tRCD
will not have much impact. However, if memory is not accessed in a linear
fashion, the current active row must be deactivated and then a new row
selected/activated. In such an example, low tRCD's can improve performance.
However, like any other memory timing, putting this too low for the module can
cause instability.
tRP:
RAS Precharge; the time required to switch from one row to the next row. For
example: switching internal memory banks.
tRAS:
Memory architecture is like a spreadsheet with row upon row and column upon
column, with each row being one bank. For the CPU to access memory, it first
must determine which row or bank in the memory is to be accessed and then
activate that row with the RAS signal. Once activated, the row can be accessed
over and over, until the data is exhausted. This is why tRAS has little effect
on overall system performance but could impact system stability if set
incorrectly.
tCLK:
This is simply the clock used for the memory. Note that because frequency is
1/t, if memory were running at 100Mhz, the timing of the memory would be
1/100Mhz, or 10nS.
EPP:
This stands for Enhanced Performance Profiles and is a new approach that
simplifies overclocking and ensures memory and platform compatibility. This
technology was defined to utilize the extra space in the EEPROM to store memory
configuration settings that are sufficient to optimize and maximize the
performance of a memory module. It basically auto detects your motherboard's
chipset and sets the memory timing accordingly. While EEP is nice, many
overclockers will be manually adjusting their memory in the motherboard's BIOS.
This memory is also Dual Channel which means better overall
memory bandwidth resulting in superior performance. In order
to benefit from this technology you will need to have a dual
channel motherboard. Non-dual channel motherboards do not
have two fully independent 64-bit memory controllers, but
dual channel boards do which means they have a 128-bit
memory interface. They can be installed singly, but
obviously performance will be much less at the same MHz.
Please remember that this memory is DDR2 and it does differ
from DDR memory in a number of ways. Please note that DDR2
memory is the new memory standard for today's motherboards. The following
explanation below goes over the general differences. It does not take into
account some of
the faster DDR/DDR2 memory on the market, but it is designed to
help you distinguish between the two:
To
begin, the maximum Data Rate is different (400MHz for DDR vs.
667MHz for DDR2), Bus Frequency (200MHz vs. 333MHz), DRAM
Frequency (200MHz vs. 166MHz), Package Type (TSOP-II vs.
FBGA), Voltage (~2.5 vs. 1.8), Prefetch Size (2 bits vs. 4
bits) and a CAS Latency (which varies quite a bit but in
general 2.5 for DDR vs. 4 for DDR2 memory). The on-die
termination is different as well. To eliminate signal noise,
DDR uses transistors that are on the motherboard whereas
for DDR2 it’s on each memory chip. The Off Chip Driver
Calibration on DDR2 memory also increases signal integrity.
While 240-pin DDR2, 184-pin DDR and the older style 168-pin
DIMM memory are all
approximately the same size, the 240-pin DIMMs and 184-pin
DIMMs have only one notch within the row of pins. The notch
in a 240-pin DDR2 DIMM is slightly more toward the center of
the module. Please keep in mind that DDR2 memory is not
backward compatible and will only fit motherboards
specifically designed for it.
Details Specifications:
Speed: PC2
8500 or 1066MHz DDR2 (533MHz)
Size: 1024MB Modules and 2GB (2x1024) Dual Channel Kits
P/N: OCZ2N1066SR2GK
Latency: EPP 5-5-5-15 1T
Package Type: 240 DIMM
Heat Spreader: SLI-Ready XTC Heatspreader*
Voltage: 2.1 or 2.35V EVP**
Warranty: OCZ Lifetime Warranty
NVIDIA Certified: Yes (more
info)
* XTC (Xtreme Thermal Convection) heatspreaders optimize
the thermal management of memory modules by promoting
greater airflow by means of micro-convection throughout what
is usually the dead air space inside conventional
heatspreader designs. In this manner, build-up of heat is
avoided and thermal dissipation of the memory components is
offloaded more efficiently through the honeycomb design. At
the same time, mechanical stability is maintained.
**OCZ EVP (Extended Voltage Protection) is a feature that
allows performance enthusiasts to use a VDIMM of 2.35V
without invalidating their OCZ Lifetime Warranty.
|