Singapore Hardware Zone

Intel Pentium II 350MHz Processor
(The next chip for overclocking?)
Reviewed by CPU-ZILLA  (9 May 99)

Technical Specifications

Clock speed

  • 350 Mhz

System Bus Speed

  • 100 Mhz

Cache memory

  • Level 1 Cache : 16K Instruction + 16K Data
  • Level 2 Cache : 512K w/ ECC @ 175Mhz

Manufacturing Process

  • 0.25 µm
SL-sSpec#
  • SL2WZ (Made In Ireland)

CPU Voltage/Current

  • 2.0 V
  • Max. current @ 10.8A
  • Power : 21.5 Watts

Math Co-processor

  • Built-in

MMX Technology

  • Yes

3D Now! Instructions

  • No

No. of transistors

  • ~7.5 million

Package type

  • Single Edge Contact Cartridge (suitable for Slot-1 motherboards)

<Introduction><The Similarities><The Test Configuration> <The Results><The RAM><Conclusion><Rating>

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Introduction

It was always very enjoyable talking to the PC Clinic Doctor, Vijay, and so one fine evening, I shared with him this thought that was in my mind after I have finished the review on the MS-6163 motherboard. I have always wondered what is the next most overclockable chip around after all the infamous SL2YK, SL2W8, SL2WY, SL32A and SL2WM. For those in the overclocking scene, they must know what I'm talking about. Others may just think that I'm performing some illegal operations and just mumbling some profound rubbish. Those are all the Spec# of the long gone Pentium II 300Mhz, 333Mhz and the Celeron 300A CPUs (although you can still find some 300A to overclock).

Before going any further into the review, some of you may have guessed what I'm going to dwell in. And yes, the PII-350 Mhz may yet be the next best overclockable CPU available in town. Hopefully this processor would not be obsolete when this article hit the web.

As I was saying, we had some discussion about my idea which prompted me to look up the Intel web site. To my surprise, I found some major similarities. At this point, most will say, "What are they? Are you sure? Prove it!?"

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The Similarities

Like most searches, I normally begin my search at the product's web site, and of course, in this case it is the Intel web site. Nowadays, the web has grown to become such a monstrous beast where you can find almost anything you want, from your everyday omelette recipe right down to the spare part number of the gear used inside a printer. It is really amazing how this information database have grown from those days when I used Lynx (a text based web browser) to surf the web. Looking back, I am feeling a little old already.

Anyway, as I was saying, I like the Intel web site. It is very well designed with just the right amount of information. Just a hint, next time, before you buy anything, look up the product's web site. If you can't find anything you want, it is likely that the product support is bad. I normally check the product's web site to see if it has the appropriate driver and technical support before plunging into any irreversible purchase. If you find a site with good technical knowledge base, it is likely that they will have all the information you want. Then again, if you can't, you can always drop by in the Hardwarezone Clinic to seek some good PC medical advice.

So, the search went on, and I found some pretty interesting results. I really do not know if they are meaningful in any sense, but logic says that they do make sense. I looked at all the specs of the available Pentium II CPUs and compared them with the Pentium II 450Mhz version. The findings proved to be pretty obvious. Here are some of my findings:-

 
SL2YK
(300 Mhz)
SL2WY
(333 Mhz)
SL2WB
(450Mhz)
Type
0
0
0
Family
6
6
6
Model
5
5
5
Stepping
2
2
2
Core Stepping
dB0
dB0
dB0
TagRAM Stepping
T6P-e/A0
T6P-e/A0
T6P-e/A0

Look at the table above. See the similarities? The SL2YK and SL2WY CPUs have been proven to be overclockable up to about 500Mhz. A large portion of SL2YK CPUs have been reported to be overclockable to 450Mhz even at 2.0V core voltage. On the other hand, a smaller percentage of overclockers reported successfully overclocking the SL2WY to 500Mhz at 2.0V, however most have to increase the voltage up to 2.2V in order to run it stable. Notice that the steppings are all the same? The steppings tell us that they are actually using the 450Mhz core, which is theoretically a Pentium II 450Mhz chip. Now, let's look at all the 350Mhz CPUs which contains the same 450Mhz core.

 
SL37F
SL356
SL2U4
SL2U3
SL2WZ
Type
0
0
0
0
0
Family
6
6
6
6
6
Model
5
5
5
5
5
Stepping
2
2
2
2
2
Core Stepping
dB0
dB0
dB0
dB0
dB0
TagRAM Stepping
T6P-e/A0
T6P-e/A0
T6P-e/A0
T6P-e/A0
T6P-e/A0

As far as I know, the SL37F and SL2WZ are boxed versions. I have not seen the rest sold anywhere in Singapore before (I guess they are tray versions, and are pretty rare). Now the big question is, which is overclockable?? I'd love to say that all are overclockable, but I can't as I don't have every single version to test out. Perhaps owners with CPUs matching the above specs could share some of their experiences through the Hardwarezone forum?

I guess I've said enough to convince everyone. Let's get on with the test!

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The Test Configuration

Listening to one of the tracks from The Phantom Menace (Duel of the Fates) while writing this article really made my blood flow with anxiety. I don't know if anyone have experienced it before, but sometimes your head is just filled with so much to say that your fingers just can't type fast enough. Gosh, sometimes I really wished that speech recognition technology would be advanced enough to input text by voice commands. I guess by now some of you may despise my articles because of the unrelated stuffs, but my point is, "Why write an uninspired article?".

In the tests, I used the latest Microstar 6163 motherboard for all the overclocking tests. Sometimes when we say that the motherboard is very overclockable, we really wonder what it means. However, in this case, we really push the motherboard to its limit by moving to all the different Front Side Bus (FSB) settings, and this would really demonstrate how overclockable the board is. I have to apologize to all the ABIT fans as I do not have the latest BX6-2 board for comparison. Also, do note that your motherboard must lower the PCI and AGP bus speeds accordingly at these different FSB settings. Otherwise, your peripherals would be toasted. Be careful.

Besides that, I used the famous Samsung GH 128Mb SDRAM and for comparison purposes, I also used my less expensive Hyundai PC-100 (64Mb x 2) SDRAM. Also, for the sake of comparison, the results were compared to my SL2YK Pentium II 300Mhz overclocked to 450Mhz.

Test Configuration

Motherboard:

Microstar 6163 (Intel 440BX chipset)

Processor(s): Pentium II - 300 Retail, batch=SL2YK, 2.0V, Malay
Pentium II - 350 Retail, batch=SL2WZ, 2.0V, Ireland
RAM:

1 x 128MB Samsung PC100 (GH) SDRAM DIMM
2 x 64MB Hyundai PC100 SDRAM DIMM

Hard Drive(s): Quantum 840AT - 800MB
Video Card(s):  ECS Riva 128 AGP
Bus Master Drivers: Windows 98 Bus Mastering Drivers
Video Drivers: NVidia Ref. Drivers Release 2.77
Operation System(s): Windows 98 (build 4.10.1998)
 

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The Results

Hey, if you have skipped the rest and arrived at this section, you have really missed out on some good stuff in the earlier section. Heh, I'm just kidding. I don't blame anyone for jumping here right away. Sometimes, it is the results that tell the whole story.

As usual, I ran the different sets of tests. I didn't run Wintune 98 tests on all the different bus speed settings, as I have said before, I didn't like the results generated by Wintune. Somehow, my basic instincts warned me of its inaccuracies. (heh, sorry, I don't place an icepick under my bed). Anyway, here are the Wintune scores.

Wintune 98 Result for Intel Pentium II 350 MHz

CPU  (1) Intel Pentium II with MMX
Video Board  ECS Riva 128 AGP
Video Mode  1024x768@16bits/pixel
RAM  128 MB
OS  Windows 98 4.10.1998 
Area Tested  Value
(3.5x100=350)
Value
(3.5x112=392)
Value
(3.5x129=451.5)
Value
(3.5x133=467)
Value
(3.5x138=483)
CPU Integer (MIPS)
1018.303
1138.531
1310.23
1355.409
1404.078
CPU Floating Point (MFLOPS)
405.9643
451.631
522.5469
540.531
560.1899
Video(2D) (Mpixels/s)
49.63787
54.90404
60.46156
62.48011
64.21648
Direct3D (Mpixels/s)
93.59107
95.18399
96.14143
96.45062
96.77773
OpenGL (Mpixels/s)
66.35886
66.89212
67.02017
67.64996
67.43007
Memory (MB/s)
610.8199
683.3156
781.5527
832.7971
850.4067
Cached Disk (MB/s)
77.27739
84.76237
99.87479
106.3939
112.0478
Uncached Disk (MB/s)
1.269655
1.472322
1.255837
1.566756
1.506166

 

As one can see, overclocking the CPU to a bus speed of 133Mhz is easily achievable. The benefits of overclocking to higher bus speeds are obvious, and need I say more? However, I managed to run some tests at 138Mhz bus frequency, but the system was showing some signs of instability even at 2.2V, and so I stopped. I doubt the little more CPU power squeezed out is of any beneficial use if the system stability is unpredictable. I attributed this instability to both the RAM and CPU. I believe I have pushed them to its theoretical maximum. Read the next section on my views about the various SDRAM I've tested.

Let's see the benefits of running the system at higher bus speeds, as compared to the normal 100Mhz bus frequency. Here, I have compared the PII-450Mhz @ 100Mhz and the PII-350 overclocked to 129Mhz bus speed (which is also running at about 450Mhz).

Comparison of Wintune 98 Results for Intel Pentium II 450 MHz @ 100 MHz & 129MHz FSB

CPU  (1) Intel Pentium II with MMX
Video Board  ECS Riva 128 AGP
Video Mode  1024x768@16bits/pixel
RAM  128 MB
OS  Windows 98 4.10.1998 
Area Tested  Value
(4.5x100=450)
Value
(3.5x129=451.5)
CPU Integer (MIPS)
1309.993
1310.23
CPU Floating Point (MFLOPS)
522.1724
522.5469
Video(2D) (Mpixels/s)
46.38165
60.46156
Direct3D (Mpixels/s)
94.37476
96.14143
OpenGL (Mpixels/s)
65.82224
67.02017
Memory (MB/s)
767.3304
781.5527
Cached Disk (MB/s)
87.665
99.87479
Uncached Disk (MB/s)
1.389292
1.255837

 

Comparing the two processors running at different bus frequencies, one could tell that the processor speed was not influenced by the bus at all (most of us should know pretty well by now). The scores for both processors were very close, although the PII-350 was a little fast since it has an extra 1.5Mhz boost, but I really doubt anyone would notice the difference. The real benefit lies in the peripherals and devices like the graphic card and the hard disk. Note the dramatic change in the 2D Video and hard disk performance. Note that in order for the peripherals to run properly, the PCI and AGP bus speeds should be lowered accordingly. Let me stress again that running at excessive PCI and AGP bus speeds might just fry your precious peripherals. However, the MS-6163 motherboard didn't give me any problems.

Next, let's look at the Winbench and Winstone scores.

Winbench 99 v1.1 & Winstone 99 Results

CPU speed
PCI speed
CPUmark 99
FPU Winmark
Winstone 99
350 MHz (100 x 3.5)
33 MHz
28.4
1800
17.7
360.5 MHz(103 x 3.5)
34 MHz
29.3
1850
18.2
392 MHz(112 x 3.5)
37 MHz
31.9
2020
19.1
409.5 MHz(117 x 3.5)
39 MHz
33.3
2100
19.3
409.5 MHz(117 x 3.5)
30 MHz
33.3
2110
19.5
434 MHz(124 x 3.5)
31 MHz
35.3
2230
19.7
450 MHz(100 x 4.5)*
33 MHz
34.9
2310
20.3
451.5 MHz(129 x 3.5)
32 MHz
36.7
2320
20.5
467 MHz(133 x 3.5)
33 MHz
38
2410
20.6
483 MHz(138 x 3.5)
34 MHz
39.3
2490
21.3

* test results for Pentium-II 300 (SL2YK) overclocked to 450MHz.

As expected, the performance of the CPU clocked at 129MHz bus speed is faster than the normal 450MHz CPU clocked at 100MHz bus frequency. The CPUmark 99 scores was somehow affected by the difference in bus speed as opposed to the processor scores generated by Wintune 98. I believe the scores must have been affected by the increased RAM clock speed. Winstone 99 scores showed little difference between the two processors at 450MHz, although the SL2WZ running at 129MHz still looks more favourable. Now, guys guys guys, before you run to SLS to grab this piece of wonder, read on to find out which RAM you should buy.

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The RAM

As most of you know by now, PC-133 SDRAM have just begun to enter the market, and you should see more of those speed demons in your local stores in the coming weeks. However, in all of these tests, I used PC-100 SDRAM currently available at this point of time. It is difficult to tell how stable your system would run if you've got yourself a crappy piece of RAM. Thus, it is important to pay more attention to RAM. Here's some comments I have on the following SDRAM available in the shops today:-

Brand
Comments
Samsung GL
Worked fine until 129MHz FSB setting. Failed at 133 MHz. Only purchase this type of SDRAM if you don't intend to overclock your system, or if you intend to do some form of light overclocking. Don't despair if you currently own this, there are still cheaper alternatives out there.
Samsung GH
This little wonder did live up to its name of being one of the fastest around. It didn't even give a single problem while I was running tests at 133MHz. It did perform well at 138MHz too, but the system was already quite unstable then. I can't seem to pinpoint which is the real problem, but I do sense that it is due to both the CPU and RAM. At 143MHz FSB, the system past the Power On Self Test (POST) but hang as soon as Windows began to load. I didn't even get the chance to take a glimpse of the Windows 98 startup screen. Those who invested heavily on this RAM, all I can say is, you can rest assure that this little baby would probably last up to the 133MHz generation, but alas, at CAS 3 setting only.
Mira
(3rd party Mitsubishi)
This RAM is actually manufactured by Mitsubishi. I didn't intend to try this seemingly unknown product until Vijay brought me shopping one Saturday afternoon. I was looking for extra RAM to fill up those empty slots. It was really cheap considering that it was rated at 125MHz. Naturally, my thoughts went wild and we discussed the prospects of pushing it to its limits. However, I was only able to run it at 138MHz. Again, I can't seem to put a finger on which is the cause of the instability, as both the CPU and RAM could be the culprit. Note that I have already pushed the CPU core voltage to 2.2V.

Hyundai
(1st party)

I bought this little baby for my own use at only 100MHz. I never thought of using it for overclocking purposes, but my oh my, I was pleasantly surprised at its performance. I had two pieces of this RAM, each was 64Mb, and bought each at different shops and time (months apart). Although this RAM was only rated at 10ns, I had little trouble using it at 138MHz @ CAS3. Once again, the system showed signs of instability at this speed. Running it at 143MHz FSB, I was surprised that it out-performed the Samsung GH RAM. Although I never successfully boot into Windows, but it passed POST and managed to give me the breathtaking view of the Windows 98 startup screen before the system locked up. I thought I was just lucky, but I repeated it several times using both the Hyundai and Samsung GH RAM, and each time, my Hyundai RAM won hands down. Somehow, Hyundai is better. Heh, I can see all the proud owners of Hyundai PC100 SDRAM smiling with glee.

There you have it. I have compared all the different RAM that I could get my hands on. Hope this section would help most of you guys/gals to decide which RAM to buy. Personally, I feel that there's little difference between them, except the Samsung GL, of course. Note that the CAS setting was 3 in all the tests.

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Conclusion

I would add this next CPU to the "One of the Most Overclockable CPUs" hall of fame. As I have demonstrated in all the various tests I've ran, you can see that this next baby is capable of doing wonders. Who knows, if you are lucky, you might just get one that runs stable at 143MHz FSB. So, what are you waiting for? If you are dying to upgrade your PC, and wants a fast and cheap system, go for it. However, do remember that overclocking is a combination of luck and art. You need luck to get a good overclockable CPU, and art in combining the right hardware. If you fail in any of the above, you may end up with an unstable piece of equipment, fit for the junkyard.

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CPU RATING

Overall Rating (Out of a maximum of 5 Star)

Performance *****
Price ****
Overclockability *****
Stability ****½
Overall Rating *****

 

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