Cache Size Impact on Performance

As we continue to look at the Athlon 64 platform with respect to Half Life 2 performance it's now time to find out how much benefit the 1MB L2 Athlon 64s gain over the 512KB L2 parts. 

Given that we've already shown Half Life 2 to be sensitive to both memory bandwidth and latency on the platform, we wouldn't be too surprised to see some pretty big differences between 512KB and 1MB L2 Athlon 64 processors.

at_canals_08
at_coast_05
at_coast_12
at_prison_05
at_c17_12
1MB L2
116.69
134.45
121.67
118.51
80.39
512KB L2
111.56
126.2
117.35
115.75
74.14

With a performance advantage as large as 8%, the 1MB Athlon 64s (and Athlon 64 FXs)  do surprisingly well under Half Life 2 when compared to their normally competitive 512KB counterparts.  While 8% alone isn't much, combine that with the advantage of a 128-bit DDR memory bus and the Socket-939 Athlon 64 platform can offer a reasonably high performance improvement over even the Socket-754 solutions. 

SSE/SSE2 Impact on Performance

Just for kicks we turned off the Athlon 64's SSE/SSE2 instruction set support to see if that impacted performance in any way:

at_canals_08
at_coast_05
at_coast_12
at_prison_05
at_c17_12
SSE/SSE2 Enabled
116.12
140.43
123.37
113.69
83.15
SSE/SSE2 Disabled
117.64
140.94
125.85
116.55
82.56

Despite minor variations in performance, it doesn't look like SSE/SSE2 is doing much for the Athlon 64 under Half Life 2.  We just had to fulfill our curiosities. 

Memory Latency Impact on Performance High End Graphics Card CPU Scaling
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  • Phantronius - Wednesday, January 26, 2005 - link

    #3

    NF4 will not be supporting AGP bud, sorry, its PCI-E from here on out.
    Reply
  • Ozz1113 - Wednesday, January 26, 2005 - link

    Ill backup the thought of putting some T-bred cores in there. My OC'd XP2600 333 w\ modded 9500 radeon system ran HL2 very well. I would have liked it to have been better, but it is not worth upgrading yet. Reply
  • Araemo - Wednesday, January 26, 2005 - link

    Hehehe.. I'll fifteenth the "Please include an AXP3200+" sentiment. Personally, I'd rather see one or two AXPs included than a complete list of athlon64s.. You can generally extrapolate the performance of a given CPU if you are given two other CPUs with the same cache/FSB/core. I know that my Mobile barton handled the game fine, but I'd like to know how far behind a cheap A64 it really is. Reply
  • miketheidiot - Wednesday, January 26, 2005 - link

    "Our standard 2-2-2-10 memory does actually offer reasonable performance benefits in Half Life 2 compared to DDR400 with higher timings such as 3-3-3-10 or the unrealistically high 3-6-6-10."

    Reasonable performance benefits? decent 2.5-3-3-10 ram can be found cheap nowdays (http://www.newegg.com/app/ViewProductDesc.asp?desc... and compared to the oczrev2 and other $200+ modules is at least $60 cheaper, in some case as much as $100 cheaper. The 2-2-2 is only 2% faster than the 3-3-3, so does that extra $60+ really offer "reasonable performance benefits"?
    Reply
  • Jeff7181 - Wednesday, January 26, 2005 - link

    #13... I wouldn't call that an error, I'd call that a difference in opinion. :) Reply
  • PrinceGaz - Wednesday, January 26, 2005 - link

    There seems to be an error on page 4- "Almost all DDR400 these days is CAS 2 memory, but older memory may have a higher CAS latency..."

    Shouldn't it say "Almost all DDR400 tested by AnandTech is premium CAS 2 memory, but CAS 2.5 and CAS 3 are more common..."
    Reply
  • Aquila76 - Wednesday, January 26, 2005 - link

    What about SLI configs? I think people looking SLI for an option may want a better idea how their CPU choice affects the dual GPU choice. Can you add SLI'd 6600GT, 6800GT, 6800 Ultra benches to the tables at the end of your article? Reply
  • Tiamat - Wednesday, January 26, 2005 - link

    Yeah, although probably unrealistic, tossing AXP's into a "low end range" comparison along side would help some people. Overall, great article! Reply
  • Regs - Wednesday, January 26, 2005 - link

    I liked the Ram latency and 64-bit/128-bit test. But I'm wondering how would 2.5 Cas would perform? Makes sense to list it since a lot of value named brand ram modules come with 2.5 CAS. I would think it would perform in-between the two, but I'm having the slightest inkling that 2.5 CAS and 2.0 CAS will perform the same.


    Can't wait to hear about multithreaded games for dual core CPUs.
    Reply
  • Jeff7181 - Wednesday, January 26, 2005 - link

    Well we can look at the other HL2 articles cause there's an XP3200 in those... but... this being a CPU oriented article I thought it would be nice to have that CPU included. Possibly even an XP3000 so we can get an idea for how it scales so I can estimate how my 2.48 GHz Mobile AXP compares. Reply

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