Test Details

Here is our venerable RAM test system based on the high performance and highly overclockable ASUS P4C800 Deluxe (i875P) motherboard:

Pentium 4 3.0GHz (800MHz PSB) processor

ASUS P4C800 Deluxe (i875P) motherboard

Memory modules operating on dual-channel mode

RAM:FSB Ratio = 1:1

PAT Enabled

MSI GeForce4 Ti 4200 128MB (Detonator driver = 41.09)

Windows XP Professional operating system with Service Pack 1

For DDR550 operation, you will require a system FSB running at 275MHz, something which not all motherboards can achieve. Also worth mentioning is that consumer Pentium 4 CPUs have their multipliers locked, making overclocking an even more troublesome/tricky task. Hence, DDR550 modules aren't every overclocker's ideal, unless they are certain of their system's capabilities. If you had the notion of overclocking the Corsair DDR550 modules to even greater speeds, the probability is small enough that you can forget about it. Already, some DDR500 modules are just high quality DDR400 memory parts qualified for such operation and the situation is not very different for Corsair's DDR550 modules too.

The following are the various memory modules used in this test, as well as their specifications and each module’s recommended memory parameters utilized as per their documentation (at default memory speeds only). The total memory capacity may differ among these modules, but at a minimum memory size of 512MB, it is more than sufficient for our conducted tests, hence performance would hardly differ due to memory capacity.

RAM Test Specifications

RAM	TWINX1024-4400(512MB x 2)		TWINX1024-4000PRO(512MB x 2)		TWINX512-3700PT(256MB x 2)	TWINX512-3200LLPT(256MB x 2)
Model	CMX512-4400 (DRR550)		CMX512-4000PRO (DRR500)		CMX256A-3700PT (DRR466)	CMX256A-3200LLPT (DDR400)
RAM Chip	Hynix HY5DU56822xxx-D43		Hynix HY5DU56822xxx-D43		Samsung K4H560838E-TCCC	Winbond W9425088BH-5
RAM Packaging	TSOP		TSOP		TSOP	TSOP
No. of IC's	16		16		8	8
Memory Organization	32MB x 8		32MB x 8		32MB x 8	32MB x 8
Memory Banks	2		2		1	1
Operated Frequency	DDR550 (default)	DDR500 (underclock)	DDR500 (default)	DDR524 (o/c)	DDR500 (o/c)	DDR400 (default)
CAS (cycles)	3.0	3.0	3.0	3.0	3.0	2.0
Tras (cycles)	8	8	8	8	8	6
Trcd (cycles)	4	4	4	4	4	3
Trp (cycles)	4	4	4	4	4	3
DRAM Command Rate (cycles)	1	1	1	1	1	1
Burst Length	8	8	8	8	8	8
Refresh(microseconds)	7.80	7.80	7.80	7.80	7.80	7.80
PAT Enabled?	Yes	Yes	Yes	No	Yes	Yes
Default Motherboard FSB Speed	275MHz	250MHz	250MHz	262MHz	250MHz	200MHz
CPU Clock Speed	3300MHz	3000MHz	3000MHz	3144MHz	3000MHz	3000MHz

To find out if Corsair has made any improvements to the new TWINX1024-4400, we down-clocked the RAM to DDR500 and compared its performance with the TWINX1024-4000PRO and the TWINX512-3700PT @ DDR500. Note that the latter RAMs are dual 256MB modules and not dual 512MB modules like the TWINX1024-4400 or TWINX1024-4000PRO. Why would this matter? If you noticed the table above, the memory organization and number of RAM chips would dictate whether the memory is a single or dual-bank memory module. Hence, the overclocked TWINX512-3700PT (which only has a single bank of memory chips) would suffer a small performance hit when compared to the other modules clocked at DDR500 and have both banks operational.

Another note we would like to mention is the Corsair TWINX512-3200LLPT RAM pair that is specified to operate at 6-2-2. However, it was a tad too aggressive for our motherboard to operate reliably. To retain stability and continue showing a comparison of where DDR400 modules perform, we used a setting of 6-3-3.

Our 3GHz CPU is an unlocked engineering sample that allowed us to select any multiplier via the motherboard’s BIOS, hence we used a 12x CPU multiplier and an FSB of 250MHz / 275MHz for testing the DDR500 / DDR550 memory respectively. For DDR400, a 15x CPU multiplier and an FSB of 200MHz was utilized. Additionally, the Corsair TWINX1024-4000PRO was able to overclock to DDR524 on a 262MHz FSB (without PAT) and we've included those results for comparison as well. Due to the various FSB and multipliers utilized, the resulting clock speeds are very different, but they do help to realize various performance levels. Most importantly, do make a mental note of the operational memory timings on each module as they sometimes play a significant role to the system performance.


Note 1: The results in this review are not cross comparable to our older reviews because we are no longer using the identical ASUS P4C800 Deluxe board that we had in the past reviews and the BIOS revision is far newer in this current board. However, we've updated all the results of previously tested modules and are reflected appropriately in this review.

Note 2: We have tried more aggressive RAM timings with the Corsair TWINX1024-4400 when operating at DDR500 such as CAS 2.5 and 6-4-4, but there were no notable differences for us to display those results.