High-end DDR is a thriving part of enthusiast-level PC hardware and vendors offer enthusiast-level solutions that fill a very real, though decided niche, market. This type of DDR exists just outside the main spectrum of the memory market, and caters to buyers with more specialized performance and overclocking needs. High-end DDR features may include high clock speeds, higher density, dual-channel certified, and low latency, just to name a few.
These higher-end DDR modules might sell for significantly more than generic DDR, but the performance payoff could be huge, depending on the requirements of the system front-side bus and memory timings, and the applications and games used. We're checking out one such product today, the OCZ PC4200 EL Dual Channel Kit, which combines the low latency and high FSB speed features into one killer enthusiast solution.
OCZ is a very popular source for enthusiast-level memory, and the company is usually at the forefront of faster DDR technologies. OCZ offers a wide range of memory products, including their Platinum, Gold, and EL (Enhanced Latency) models that offer many different speeds, densities and formats for the enthusiast buyer. The OCZ PC4200 EL Dual Channel Kit offers 2x512-MB of 533 MHz-capable DDR, designed for the dual-channel Intel platforms, and comes with many high-end features and specifications.
The memory timings are the most obvious, and OCZ states that CL2.5-4-4-7 is supported at up to a 533 MHz DDR clock speed at 2.8V. This is a pretty amazing claim, as most other vendors stick to CL3 for their PC3700 and up enthusiast DDR. In our testing, both 500 and 533 MHz are stable at CL2.5, and this is some of the highest-end DDR we've ever used. Another nice feature is the ability to run at CL2 for 400 MHz operation, thereby maintaining high performance at lower clock speeds. These DDR modules feature gold heatsinks for stability, and OCZ has also included the memory model and timings on an easy-to-read sticker.
OCZ also promotes PC4200 EL DDR using a variety of terms and features. The first is the "EL" suffix, which translates to Enhanced Latency, and is pretty evident in the CL2.5@533 MHz specification. Other features include ULN2 (Ultra Low Noise) that reduces noise at the PCB level, HyperSpeed or modules optimized for the highest possible frequency, Dual Channel Optimized (qualified for use in dual-channel configurations), and EVP (Extended Voltage Protection), which allows DDR modules to handle higher voltages. The EVP feature is important, as this includes protection under OCZ's Lifetime Warranty, assuming you do not exceed their specifications. The PC4200 EL modules are rated at up to 2.9V, which is great news for hardcore overclockers.
The main criteria of higher-than PC3200 DDR is that it lives up to its clock speed billing and performs well when overclocked. Our testing consisted of two different scenarios, one for the benchmarking portion and the other for real-world overclocking. The latter consisted of overclock testing on an i875P board to 500 MHz DDR speeds (due to a 255 MHz max FSB) and then further testing to 533 MHz on an i848P motherboard, which allows a bit more freedom in selecting DDR clock speeds. In each test, the OCZ PC4200 EL passed at the rated memory timings and at a 2.8V DDR voltage.
To ensure a directly-comparable set of performance benchmarks, the latter overclock testing maintained a close-to 3.4 GHz clock speed for our Pentium 4-3.4C GHz reference CPU, by using its unlocked nature to reflect the performance impact of higher FSB and memory speeds. This resulted in the following overclocked speeds: 14x243 (3402 MHz), 15x226 (3399 MHz) and 16x213 (3408 MHz), along with standard 17x400 MHz testing. This not only gives the OCZ PC4200 EL a good workout, it also allows us to evaluate FSB/DDR performance effects, irrespective of the actual processor core speed.
The overclocked benchmark section is informational only and it's really just the OCZ PC4200 EL competing against itself, but at the 400 MHz level, we introduce a few different competitors. Higher bus speeds may also enact a penalty to memory timings, and for reference, here are the different memory brands and their benchmarked bus speeds and timings.
Also keep in mind these timings use a high-end i875P motherboard with PAT and dual-channel modes enabled. The DDR timing and speed requirements are much stricter under this scenario, than when using more forgiving dual-channel i865PE/nForce2 or single-channel K8T800-based motherboards. Different motherboards may also exhibit varying results, but due to the high-end memory voltage and CPU overclocking features on the Soyo P4I875P Plus Dragon 2 Platinum, it is indicative of an enthusiast-level i875P motherboard.