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PDP Systems PDC22G4200+XBLK DDR2
Date: Jan 14, 2005
Author: Jeff Bouton
Introduction and Product Specifications

When DDR2 first saw the light of day, the memory marked the next level in DDR technology.  However, with improved frequencies, lower voltage requirements and improve packaging also came higher latencies.  With intial offerings coming in at CAS 4-4-4-12 and even higher, the performance improvements over DDR1 were minimal at best.  There was also a significant price increase over DDR1 that became a stumbling block for DDR2 as it really didn't make sense to pay more for the same relative performance.  Today, the DDR2 sector has evolved into the next phase of lower latency offerings.  As expected, we are seeing latency improve, making the case for upgrading to DDR2 a bit more palatable.  Now, it is not uncommon to see 3-3-3-8 timings as the norm, and as we'll see today, there are even lower latencies to be had.

The latest DDR2 modules to hit our test bench come from PDP Systems.  While new to the HH labs, PDP systems has been in the business of memory since 1985, proving they are no strangers to the industry.  What they sent us was a 2GB set of their Patriot Dual-Channel DDR memory rated at a CAS latency of 3-2-2-4 at DDR533.  This was by far the lowest latency rating we've seen to date and were anxious to put them to the test.  In the coming pages we'll put PDP Systems' PDC22G4200 Patriot memory through its paces to see if it can live up to its claims.  While we won't give anything away just yet, we'll say we did encounter a few surprises along the way.  Let's get started.

Specifications of PDP Systems' PDC22G4200+XBLK
2GB of Low Latency DDR2...WOW!

Part Number:
CAS Latency:

Test Voltage:
Heat Spreader:
Error Checking:
2GB kit (2x1GB)
128M x 64-bit
3-2-2-4 @ DDR533
4-3-3-12 @ DDR700
1.8-2.0 V
Red Aluminum
DDR2 533MHz (PC2-4200)
240-pin DDR SDRAM

As we mentioned above, the PDC22G4200+XBLK are a high-performance, low latency dual-channel DDR2 set.  These modules come rated to run CAS 3-2-2-4 at DDR533 and can run at DDR700 with CAS 4-3-3-12 timings.  The modules consist of eight 128MB chips per stick in a double-sided layout.  PDP uses Micron's MT16HTF6464AY-53E chips in the Patriot low latency DIMMs, which, interestingly, are rated for PC2-4200 at CAS 4.


We're not sure what PDP does to acheive such low latencies, running PC2-4200 at CAS 3, but we gather steps are taken in the PCB construction to make sure the chips run in the most ideal signal conditions.  This is an impressive feat and could prove interesting as we start the testing phase of these chips.

Next, let's take a look at the HH Test Bed and how we configured the system and our tests.

HH Test System and Configuration

Compatibility Testing:  To test the stability and compatability of the Patriot Memory, we installed it in a series of motherboards to see if we encountered any issues.  For this, we installed the PDC22G4200+XBLK into three of the most recent motherboards we've reviewed.  The first was an ASUS P5GDC-V Deluxe I915G, followed by an MSI I915P Neo2 Platinum and a Foxconn 925XE7AA-8EKRS2 I925XE, which we also used for all benchmarking.  In each test scenario, we did not experience any odd behavior whatsoever with any of the boards. 

When we installed the memory modules into our Foxconn test board, we found when we set the memory timings by SPD in the BIOS, the system defaulted to the proper 3-2-2-4 timings.  Once Windows loaded, we used CPUZ to take a closer look at the memory settings and SPD programming.  What we found was that even though the memory was running at the expected 3-2-2-4, the SPD is actually set for 3-2-2-3.  Currently, our test board is at the lowest possible settings in the BIOS, but if future updates unlock lower settings, these modules may be able to go even lower.

HotHardware's Test System
Not all are created equal...

Socket T - Pentium 4 530 (3GHz)
A Foxconn 925XE7AA-8EKRS2 Motherboard
I925XE Chipset

Corsair XMS2-PC5300 1GB
Radeon X600 XT
On-Board 10/100/1000 Ethernet
On-Board Audio
WD 30GB Hard Drive
Windows XP Pro SP2
ATi Catalyst 4.12

How we configured our test systems:  When configuring our test systems for this article, the first thing we did was enter the system BIOS and set each board to their "Optimized" or "High-Performance Defaults".  The hard drives were then formatted, and Windows XP Professional (SP2) was installed. When the installation was complete, we hit the Windows Update site and downloaded all of the available updates, with the exception of the ones related to Windows Messenger.  Then we installed all of the necessary drivers, and removed Windows Messenger from the system altogether.  Auto-Updating and System Restore were also disabled, and we setup a 768MB permanent page file on the same partition as the Windows installation.  Lastly, we set Windows XP's Visual Effects to "best performance", installed all of our benchmarking software, defragged the hard drives and ran all of the tests.  Throughout all of our standard benchmarking, we had the memory voltage set to 1.9v.  When overclocking, or experimenting with lower latencies, we set the memory voltage to 2.0v.

Peformance Testing by SPD

One thing we wanted to note before starting the benchmarking phase was that while PDP Systems sent us a 2GB Dual Channel kit for review, we did not have any other 2GB sets on hand to compare it to.  So, we cannot give a real apples to apples comparison in the peformance section of this review.  What we did do, however, was include the results from a recently released 1GB DDR2 review to give a frame of reference, which still can offer a good comparison.

Performance Comparison with SiSoft SANDRA 2004
Raw Bandwidth

We began our testing with SiSoftware's SANDRA, focusing our attention on the Memory Benchmark.  We started by setting the memory by SPD, running at 3-2-2-4 timings.  As we noted above, for comparison, throughout the review we compared the peformance to 1GB of Corsair's XMS2 PC5300 and PQI PQ24200 memory as a reference point, matching timings and speed as close as possible.



XMS2-5300Pro 1GB

The Patriot Dual Channel PC4200 was the fast set out of the bunch, with the Corsair coming in a close second.  The PDC22G4200+XBLK posted a lead of approximately 30MB/s over the Corsair XMS2 series, as it should with more aggressive timings.  We did try both comparison DIMMs to see if they could run at 3-2-2-4, and they could not, even if we increased the voltage to 2v.

Performance Comparison with PCMark04
Overall Memory Score

Continuing the synthetic testing, we loaded PCMark04's memory performance module exclusively of its other components.  Each set of memory was set to run at its SPD timings as noted.

The PDP Patriot Memory walked away with a more sizeable lead than we saw in SANDRA, topping the Corsair memory by 46 points thanks to its lower latencies.


In-Game Performance Comparisons With Wolf: ET
System Memory Affects Frame rates?  You Bet!

In our next test, we ran Wolfenstein: ET TIMEDEMO with the graphics qualities set to their lowest settings.  This helped remove the effects of the video card from the equation, focusing more on the actual memory and CPU performance.

In this batch of tests, the Corsair memory slipped to the last position as the PQI modules took close to a 4 FPS lead.  The Patriot memory added an additional 3.5FPS to that, taking the top seed at close to 120FPS.

Overclocking - by SPD Testing

For next round of testing we set each kit to run with their SPD timings and raised our test system's FSB as high as possible.  This is where the PDP Patriot modules shined.  We managed to hit a solid 233FSB, increasing the memory to 621MHz DDR.  This was an excellent gain, especially without having to tone things back with the timings.  The only thing we did was set the memory to run at 2v and the modules ran great and remained stable through the next range of tests.

Performance Comparison with SiSoft SANDRA 2004
Raw Bandwidth


PDC22G4200+XBLK (3-2-2-4)
233MHz FSB / 306MHz (DDR621)

PQI24200-1GDB (3-3-3-8)
220MHz FSB/ 293MHz (DDR586)

XMS2-5300Pro (3-3-3-8)
216MHz FSB / 288MHz (DDR573)

Naturally, at significantly higher bus speeds than the reference modules, the PDP Patriot series was the fastest set in the group.  Additionally, these were the only DIMMs to top even SANDRA's internal set of memory scores.  On average the memory ran at a 5800MB/s at DDR621.

Performance Comparison with PCMark04
Overall Memory Score

We saw a sizeable gain in score with PCMark04's memory module, obviously beating out the competitors as well as posting solid gains over its stock results.  We saw a healthy 858 point increase, average out to a 16.68% boost in performance.

In-Game Performance Comparisons With Wolfenstein: ET
System Memory Affects Framerates?  You Bet!

In the last test, we saw less drastic differences in score with Wolfenstein: ET.  Here, the closest margin was between the PQI and PDP modules, with the Patriot series take a 5 FPS lead.  Overall, the PDP Patriot memory added 13.6FPS over its stock results, equalling 11.3%.

Overclocking - Highest Stable Clock

For our final round of tests, we set the PDP Patriot memory to run at 4-3-3-12 and compared it to the other modules at 4-4-4-12.  We then raised our test system's FSB as high as possible, resulting in 251MHz, the highest attainable for this board.

Performance Comparison with SiSoft SANDRA 2004
Raw Bandwidth


PDC22G4200+XBLK (4-3-3-12)
251MHz FSB/336MHz (DDR672)

PQI24200-1GDB (4-4-4-12)
251MHz FSB/336MHz (DDR672)

XMS2-5300Pro (4-4-4-12)
251MHz FSB/336MHz (DDR672)

In this round, the PDP Patriot and Corsair memory managed to come up virtually tied, with a slight edge in favor of Corsair.  The Patriot modules maintained a 1MB/s lead in the Integer test while slipping 4MB/s in the Floating point segment.  The PQI memory weighed in an average of 100MB/s slower than the other two sets. 

Performance Comparison with PCMark04
Overall Memory Score

Here, the PDP Patriot memory lagged Corsair by a small 7 point margin, where the PQI set fell by 85 points.

In-Game Performance Comparisons With Wolfenstein: ET
System Memory Affects Framerates?  You Bet!

Our final test was with Wolfenstein: ET, where the PDP Patriot memory eked out a top spot by a fraction of a frame over the Corsair XMS2 series modules.  Again, the PQI modules came in last, slipping by roughly 2FPS, a very close third position.

Performance Analysis and Conclusion

It seems that while there are a number of big name companies on the market pushing quality DDR2 memory, there is a healthy group of lesser known competitors as well.  The latest is PDP Systems and their Patriot Series of Dual-Channel modules.  These are the lowest latency modules we've seen to date and they performed well above any expectations we may have had.  The modules boasted excellent performance results across the board and managed terrific overclocking potential as well.  Stability was equally impressive without a single glitch in all of our testing.  What really stood out to us was the overclocking performance with low latencies, where the modules easily topped our comparison chips by a decent margin. 

If you are looking to make the move to DDR2 and want to do it right by getting yourself a 2GB set, the Patriot PDC22G4200 series are an excellent choice.  Granted, 2GB of DDR2 will set you back close to $600, but, in the end, that's actually a pretty good price for a 2GB kit of this quality.  Currently, the Patriot series are widely available at a number of online retailers, including LexSys Micro who providing the product for testing.

We give the PDP Systems Patriot PDC22G4200 DDR2 memory Hot Hardware Heat Meter Rating of a...


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