PC2-8500 worthwhile?

Hello all!

I'm trying to educate myself on the recent development in the harware department and have come to memory.

With an Intel motherboard in mind, which can handle both 800 MHz and 1066 MHz memory modules, which is to prefer:

PC2-6400 CL4 or
PC2-8500 CL5 at 1.5 the cost?

Should the FSB of the processor preferrably match the frequency of the memory modules (guess not since there are FSB 1333 MHz processors)?

Thanks for your time,
Christer

 

Thanks Dennis!

I'm going away from home tomorrow morning on a trip to Germany. Will dig into it (not Germany ... ... the memory research) on Sunday evening but keep the suggestions coming.

Christer

 

Rockster2U,
my mind works in mysterious ways ... ... !

I thougth that I would need to go for DDR3 to utilize the full potential of the 1333 FSB capability of the motherboard and processor (Intel E6850) but X-bits labs complicate things by stating that the bandwidth of DDR2 PC2-6400 memory modules in dual channel mode is higher than that of a 1333 MHz FSB. I haven't read all of it yet but I'm sure that there are a lot of BUTS (a single T only).

Anyway, due to budget limitations, DDR3 are a bit too expensive and both memory modules I consider are DDR2:

Corsair TWIN2X2048-6400C4DHX which I found at a "local vendors" webpage but when I looked further, I was surprised to find Corsair TWIN2X2048-8500C5D which seems to stretch DDR2 a bit (non JEDEC standard).

From page 2 of the X-bits article I quote:

This is exactly what I'm trying to prove to myself but with a DDR2 module of a higher frequency.

Does this mean that Corsair are the "bad guys on the block" and that Corsair TWIN2X2048-8500C5D really is worth the money (DDR3 performance at DDR2 price) even with a higher latency?

Matt,
I too am trying to build a system that is "above average" but still won't lose half its value in a year due to price drops. The computer will probably not be used for "high end tasks ", not even gaming and DDR2 PC2-6400 will be sufficient.

However, as Rockster2U has pointed out, I think too much ... ... and wondered if PC2-8500 with a latency of 5, really is faster than PC2-6400 with a latency of 4? If you do a little number juggling, which probably is not the way to do it but the result indicates to me that the difference is not 33% (8500/6400=1.33) but more like 6% (8500/5x4/6400=1.06).

Now, please, tell me to stop thinking!

Christer

 

I took a quick peak into a few other articles at X-bit labs. A frequently used word is "overclocking" and that is not what I am looking for. The memory modules should be "auto detected" and made to work fine on the motherboard when installed by an average user who can't even spell owerkloking.

Christer

 

I too am leaning towards XP but will probably not "go for it" until SP3 has been released. I will then slipstream SP3 into my original RTM CD (and if possible, keep IE7 out of it). Indications are "first half of 2008" for the release of SP3 which is fine by me but your plans for Christmas are ruined. I will not consider Vista until I feel that XP no longer does what I need but the hardware will be "Vista Certified ", giving me the option to change my mind.

(Before anyone comments on it: I will put my trusted but disused WinME back on the old BOAC and use my WinXP on the new BOAC.)

Christer

Edited - this a bit off topic for this section (hardware) but to elaborate a bit:
In Sweden, XP SP2 OEM costs SEK 1349 (USD 208) compared to Vista Home Premium OEM at SEK 1095 (USD 168) or Vista Ultimate OEM at SEK 1749 (USD 249). Would it make me a nut to not buy Vista "any flavour" OEM with my new hardware, even if I want to wait for SP2 ... ... before I need it or want it?

 

Matt,

If I choose to install XP, waiting for SP3 (slipstreamed) will result in a cleaner installation.

If I at a later date choose to install Vista, waiting for SP2 (no typo) in Vista will hopefully result in drivers for my new BOAC that will actually work. I'm a bit ... ... here but SP1 in Vista is just around the corner and SP2 in Vista will possibly be a reality when I get around to installing.

Sorry for the confusion!

Christer

 

Well, for anyone interested, my conlusion on PC2-8500 being worthwhile or not:

Trying to "optimize" the build on price/performance, I have looked at the different components to find the sweetspot (where the price/performance ratio goes ballistic). When it comes to processors:

AMD Athlon64 X2 5600+ at SEK 1170 (USD 180)
AMD Athlon64 X2 6000+ at SEK 1360 (USD 209)
AMD Athlon64 X2 6400+ at SEK 1830 (USD 282)
The 6000+ seems to be at the sweetspot but it is a 125 W design and I think I would opt for the 5600+ which is a 89 W design (runs cooler). Checking the CPU tests at Toms Hardware, it has basically the same performance as the FX-62.

Intel E6550 at SEK 1430 (USD 220)
Intel E6750 at SEK 1590 (USD 245)
Intel E6850 at SEK 2270 (USD 349)
The E6750 seems to be at the sweetspot.

Compared to the RAM modules:
PC2-6400 at SEK 995 (USD 153)
PC2-8500 at SEK 1590 (USD 245)
(The PC2-8500 modules are not an option for the AMD solution.)

The CPU tests at Toms Hardware reveal that the E6750 has the better "overall" performance compared to the Athlon64 X2 5600+ but at a price premium, SEK 420 (USD 65).

The motherboards don't cost the same:
for the AMD processor, Asus M2N-SLI DeLuxe at SEK 1 095 (USD 168)
for the Intel processor, Asus P5N-E SLI at SEK 1 149 (USD 177)
The price premium if I go Intel is SEK 54 (USD 8)

The total price premium if I go Intel is SEK 474 (USD 73)

The price premium for the PC2-8500 modules is SEK 595 (USD 92) compared to the PC2-6400 modules and the performance gain is questionable.

The bottom line is that the price premium for going Intel might be justifiable but the price premium for the PC2-8500 modules can be spent more wisely, right?

Christer

By the way, I have no immediate plans for a new build and will wait and see what happens with the new AMD 65 nm, 45 W design.

 

I have studied the datasheets for a few memory modules and suspect that many people buy "better" memory modules but aren't aware that they need to change some settings in BIOS for them to be better. A few examples from Kingston:

KVR800D2N5K2/2G
If you install these modules in fresh build, they will run at 1.8 V at 800 MHz and CL5 (other timings seem to be a secret).

KHX6400D2K2/2G
If you install these modules in fresh build, they will run at 1.8 V at 667 MHz and 5-5-5-15 timings. You need to increase Vdimm to 2.0 V to get them running at 800 MHz and 5-5-5-15 timings.

KHX6400D2LLK2/2G
If you install these modules in fresh build, they will run at 1.8 V at 667 MHz and 5-5-5-15 timings. You need to increase Vdimm to 2.0 V to get them running at 800 MHz and 4-4-4-12 timings.

As I understand it, the latest nForce chipsets from nVidia (590/680) and probably chipsets from other manufacturers can detect not only SPD (Serial Present Detect) programmed settings but also EPP (Enhanced Performance Profiles) settings and automatically adjust the BIOS setting for the modules to run at the higher frequency and tighter timings.

How many "amateur builders" will dig deep enough to uncover this?

How many "amateur builders" will run their nice 800 MHz 4-4-4-12 memory modules at 667 MHz 5-5-5-15?

Christer
(who has used a lot of words in this post that he really doesn't understand ... ... )